Chicago: Anatomy of a Building and its Collapse PDF Training Aid
The recent post titled: Chicago: Anatomy of a Building and its Collapse has been receiving a considerable amount of attention as the post makes its way throughout the fire service eMedia sites, links, likes, shares and commentary circles, with over 6,000 views in the past 24 hours on various sites.
It furthers the premise that I have advocated my entire career and that is the fire service continues to recognize the need for increased knowledge, training, insights and skill sets related to building construction and its diametric relationship to firefighter, command risk management and operational safety.
And that we need to learn from each and every incident response,operation and run….Let’s continue to gain learnings and insights from not only this event, but from the vast resources of published LODD investigations, after-action reports, case studies, near-miss events and close-calls; for each has a lesson that we can use on our next call.
In order to provide support for continuing training and insight opportunities, I’ve developed a PDF download of the Chicago: Anatomy of a Building and its Collapse article in its entirety.
A power point program will be forthcoming to accompany both media items.
The tragic events in the City of Chicago on Wednesday December 22, 2010, when Chicago Firefighter Edward J. Stringer – Engine Co.63 and Firefighter/EMT Corey D. Ankum, Truck Co.34 were killed in the line of duty while operating at a structure fire in an abandoned one-story brick building in the 1700 block of East 75th Street on the City’s South side, exemplifies the demands, challenges and sacrifice that come with responsibilities, duty and sworn obligation that distinguishes the honorable profession of being a firefighter.
The fire was first reported at about 06:48 hours during the night and day tour shift change, with companies arriving at 06:52 hours reporting moderate fire in the buildings northeast corner. The single story commercial structure was vacant, however it was readily known that squatters were known to seek shelter in the abandoned structure especially give the harsh weather being experienced in the city. The fire was quickly contained at approximately 07:00 hours according to published reports, and radio communications, with coordinated suppression, search and rescue and ventilation operations being conduction by companied both within the interior and on the roof.
It was during this phase of operations that a mayday was rapidly communicated at 07:07 hours after a portion of the roof and rear masonry wall unexpectedly collapsed sending personnel operating on the roof riding down with the collapse and trapping four firefighters within the confines of the interior voids. RIT was immediately deployed at the scene for the trapped personnel with reports of numerous firefighters injured by the collapsing wall into the alley way on the Charlie and Delta sides.
Non-Bearing Sidewall lateral "push-out" collapse resulting from the inward failure of the roof system into the interior
The incident escalated quickly to a 3-11 alarm with subsequent manpower and resources dispatched to provide immediate collapse search, rescue, extrication, medical treatment and incident scene management and support. The resulting structural collapse killed firefighters Stringer and Ankum and injured seventeen other firefighters.
In this incident the Rules of Structural Fire Engagement were clear and resonated with the commitment and resolve that define the American Fire Service. Companies committed to tactical deployment operations consistent with departmental operating procedures and policy that required interior fire suppression, in conjunction with a coordinated interior search and rescue task assigned and supported by roof ventilation. Although the one-story brick building was clearly abandoned and vacant; it was not known if it was unoccupied, thus the tactical search and rescue assignment. According to Chicago Fire Commissioner Robert Hoff, firefighters entered the burning structure because of reports there may have been squatters inside the old laundry and cleaning facility.
By all indications this alarm was a conventional fireground operation being conducted in a fashion consistent with the operating procedures and protocols of the Chicago Fire Department (CFD), executed in a formulative manner that was predicated upon similar past building performance and operations successes. Various news reports and audio recordings of fireground communications identified that first arriving companies recognized the building and occupancy type and were aware that the building had a characteristic bowstring truss roof system in the rear (Charlie side) of the occupancy. CFD procedures dictate identification of the degree of fire involvement or impingement within the truss loft area (concealed or open area located within the open void space of the truss chords between the underdeck of the roof and the bottom chord of the truss) to determine risk and impact on further tactical operational deployment and task assignments.
The CFD is adeptly aware of the historical characteristics, hazards and safety concerns associated with firefighting operations in buildings of bowstring truss construction. The Chicagoland area has an abundance of vintage building types with an array of occupancies that have characteristic small and large span structural bowstring truss systems.
CFD Firefighters know bowstring truss roofs only too well because of the risk of collapse. Twelve years ago, two firefighters died when the bowstring truss roof collapsed on them while fighting a fire in a tire and auto repair shop in Beverly. The roof in the Beverly fire was already ablaze. In the case of 1744 East 75th Street, companies did not identify any fire extension or impingement within the truss loft area during initial phases of deployment and initiated tactical operation assignments accordingly based upon the fire location and strategic incident action plan.
FF Ankum and FF Stringer were killed by the crushing weight of the collapsed roof. With a structural support system comprised of wood timbers configured in a bowstring style truss system, this structural support system and construction style was common in the late 1920s when the building at 75th and Stony Island in South Shore was built. The truss is arched like a bowstring and provides a clear span within a room or large compartment floor area without intermediate vertical support columns. The structural truss component is typically anchored along the exterior walls where the roof load is transferred to the vertical walls and transmitted down to the foundation.
The building and occupancy at 1744 East 75th Street however did have a risk profile not related to its occupancy type and one that was not readily known to operating company or command officers during the initial stages of fireground operations; that this building was in state of disrepair and had received numerous citations and notices of action. The unstable nature of the building, the apparent poor condition of the roof and inherent deficiencies in the structural support system and construction created an operational risk profile that could not be identified readily through conventional size-up by arriving and deploying command or company officers.
It was reported that the city had previously cited the building owner for numerous building code violations; including failing to maintain the roof- which, according to the violation, had holes and was rotted and leaking. The violation also indicated the roof trusses were vented and rotted. It is not known if pre-fire plan information was readily available to responding companies or if recent first-due company level inspections or walk-thru had been initiated or completed.
In an effort to provide timely learning’s from this incident and in advance of the more thorough and detailed subsequent investigative reports and information that will be forthcoming in the months ahead, I’d like to provide some insights and basic information to increase firefighter, company and command officer awareness and knowledge related to the operational concerns for similar buildings with bowstring truss structural roof systems and share some observations related to presumptions deduced from incident scene photos. The representative insights derived from this incident are in no way meant to analyze or offer criticism towards any element of the operations conducted at 1744 East 75th Street; but are provided to increase your knowledge of building features to support operations at similar structures and occupancies so as to reduce the likelihood of other history repeating events (HRE) in your jurisdiction or response district.
These insights are based upon an analysis of incident scene photographs, internet based images and maps from Google, Bing along with video and audio media clips. Interpretations and assumptions made (especially related to dimensions, size and configurations) are representative to provide content to scale and similarities with other typical construction features in an effort to advance firefighter knowledge.
Aerial view of the 1700 Block of East 75th Street and Collapse Area
Aerial Photo of the Collapse Zone looking from the Delta Side. The Rear alleyway on the Charlie Side runs parallel to East 75th Street.
Anatomy of the Building and Collapse
The structure at 1744 East 75th Street appears to have been part of a larger series of collective occupancies and structures that previously spanned the entire city block, sharing construction features and commonalities consistent with construction methodologies and practices in the 1920’s through the 1940’s. An aerial view of the 1700 block of East 75th Street clearly shows the series of one-story brick buildings sharing both common party walls and possibly independent bearing walls between separate occupancies, with their distinctive roof profiles and varying square footage of floor area.
The Alpha [A] side is East 75th Street with a common parallel alleyway located on the Charlie [C] side. The collapse area appears to have been approximately a 60 feet (depth) x 50 feet (width) for an area of ~ 3000 square feet. The outward failure of the Delta [D] side load bearing also occured as the roof failed inward into the building. Published reports indicated the roof system present in the immediate collapse zone was comprised of bowstring truss components. This is evident in a series of fireground photos that clearly depict the remnants of a shallow depth built-up chord bowstring truss comprised of timber wood components.
Built-up Bowstring Timber Truss Component
Truss resting along a interior support pilaster Bearning End of Bowstring Truss Component
Bearing End of a built-up Bowstring Chord Truss
It appears the bowstring wood truss components rested on top a series of four (4) brick wall pilasters and pocketed within the east and west brick bearing walls. The north non-bearing brick wall appears to be a three wythe solid brick wall, with the bearing walls running east-west. The non-bearing brick wall running parallel to the alley way was the main portion of wall that collapsed outward as a result of the inward collapse of the truss roof support system, wood rafters and plank roof deck. The inward momentum created by the downward forces of the failing roof area, pushed outward the entire north wall face, which based upon the modular charactoristics of the brick and mortar, most likely caused the wall to collapse in sizeable sections (outward collapse as well as disintegrate into smaller projectiles with a classical curtain failure. Photos suggest the wall failure resulted in a collapse zone that spanned the entire narrow alley way from wall to wall (estimated at 18 +/- feet) leaving no room to escape the lateral failing wall collapse without running in an east and west direction only.
The single story size of this common Type (Class) III Ordinary Construction building which is estimated at 18 feet in height appears to have had a parapet wall raising above the roof line, consistent with design features found in buildings of this vintage.
The single story height coupled with the square foot floor/roof area, any loss of structural integrity of a single truss component would likely cause the compromise or collapse of adjacent truss components and connective decking planks due to the interdependence and connectivity of the roofing support (trusses), purlins, rafters and roofing planks and outer membrane system.
Typically the failure of one bowstring truss span will compromise or cause the collapse of each adjacent truss to either side of the original affected truss causing the failure of a sizeable roof area.
Companies operating on such affected roof area areas are subject to high risk and vulnerability should the roof area fail. Refer to the incident conditions and structural collapse from the Waldbaum’s Collapse, FDNY August 2, 1978. Go to the incident overview at Commandsafety.comHERE.
In smaller square foot commercial occupancies that have shallow depth bowstring truss components and both limited spans (less than 100 linear feet clear span) and number of trusses (six or less) the likelihood of a catastrophic roof collapse should be considered highly predicable in all incident action plans and during incident status monitoring.
The loss of load bearing and load transfer capabilities at these wall connections can contribute towards failure and collapse conditions. The end connections points (end cap or end shoe) of a bowstring truss are critical towards maintain truss performance and structural integrity.
The loss of truss axial orientation, resultant excessive deflection, loss of integrity of chord/ web geometry and connection points can lead to failure mechanisms and a cascading effect due to transferring of loads and possible overstressing and directly lead to subsequent failures.
Photo examination further identifies the presence of concrete masonry units (CMU) evident in a number of incident scene images that suggests renovations and alterations at some point in the building’s recent history that may have had an impact on the building’s integrity or performance profile ( postulated, actual or forecasted).
It should be noted that fire service personnel should have a high degree of respect for the danger and susceptible risk imposed by compromised or failing bearing and non-load bearing walls.
Collapse zones must be established and access controlled based upon physical incident scene layout, access and proximal exposure structures.
All fire service personnel should have awareness level training and an understanding of recognizing collapse indicators for buildings of masonry construction and tactical safety considerations
Company and Command Officers must have a higher level of knowledge and training to be able to recognize subtle or obvious construction, conditions or indicators that will affect IAP, strategic, tactical or task assignments and be able to act upon those indicators with immediacy and urgency as conditions and risk dictate.
The Collapse Zone should be at a minimum be equal to the full height of the exterior masonry wall face and also take into consideration additional distance due building material momentum, bounce and toss due to individual bricks, steel lintels and other components and materials acting as projectiles and traveling distances greater than the defined “collapse zone”.
Collapse Rescue Void Search Operations
The sheer weight and mass present in a brick wall presents significant probability of debilitating injuries and death if caught in the collapse zone by falling wall sections or brick projectiles.
A standard common brick may weight 4.5 – 6 lbs. each. An 8 inch wide brick wall may weigh upwards of 83 pounds per square foot (PSF).
For illustration purposes; A 50 foot long wall x 18 feet in height constructed with a solid 8 inch wide brick non-load bearing wall (assuming 15% openings for doors/windows) would have an estimated dead load weight of 63,500 lbs. (31.75 ton)
Fire Service personnel must be aware of the three common exterior masonry wall mechanisms of collapse that include; outward monolithic wall collapse, inward/outward wall collapse and curtain fall collapse. Building height, width (wyth) of the wall, bearing or non-bearing wall types, weather conditions, fire impingement or exposure and age, reinforcement, deterioration/integrity of mortar joints etc., all have influencing effects on the actual manner in which an exterior masonry wall will collapse.
In smaller single story commerical structures of Ordinary Type III construction, the 90-degree monolithic and/or curtain-fall wall collapse can be expected.
The probability of void spaces being present due to a catastrophic collapse of a bowstring truss roof system are predicated upon the presence of interior space features such as shelving, equipment, products/materials and any small height area partitions or physical barriers (that may even extend upwards to the understructure of the truss chord) and the manner in which the structural bowstring truss component and integrated roofing system fail or compromise from the outer wall bearing points. (pancake, lean-to)
The collapse of the roofing deck system resulting from a compromise or collapse of the bowstring truss system may cause under some circumstances a longitudinal failure or cracking of the upper masonry wall either along the line of the roof/parapet interface or in an area immediately beneath this point.
The resulting impact due to dynamic load transfers may cause the upper masonry wall and/or parapet to collapse inward while simultaneously causing the lower masonry wall section to collapse in an outward manner into the exterior collapse zone.
The manner in which the exertion of force applied to the outer masonry wall during the mechanism of the collapsing of the roofing system will determine the extent of force, failure and degree of brick material that will be deposited at the base of the wall and beyond within the collapse zone.
Wood Roofing Planks and outer membrane with visible Wood Roof Rafters as part of the Roofing System
Refer to the following NIOSH LODD Reports related to brick wall or component & collapses;
Built-up bowstring trusses such as the ones that appear to have been present at 1744 East 75th Street came in varies sizes related to the dimension of the structural wood components utilized (heavy timber or built-up), the depth of truss related to its span and its load bearing design/capacity (and the subsequent truss loft void created by the truss top and bottom chord as well as the manner in which the truss web members were held together, the connection methods utilized and the manner in which the truss component was designed to be seated in its load bearing position (pocketed or surface load bearing).
The following photographs provides a representative example of a heavy timber truss showing the steel U-shaped end shoe (bolted to the bottom chord) seated on the bearing plate of the pilaster. This is a common connection point and is a critical area for maintaining the structural integrity and stability of the roof system. These load bearing points are susceptible to age related deterioration of the bearing surface, shoe connection/chord connection, loss or degradation of the bearing wall conditions, decay or deterioration of the end connections that adversely affect the structural stability of the top truss cord to transfer the thrust loads imposed upon this connection into the bottom chord.
Typical Truss End w Bottom Chord, Steel End Shoe and Load Bearing Plate on a Pilaster
Note: the crack in the bottom wood chord running from the steel shoe and bolt connections, indicating an area of concern
A bowing or outward thrust of brickwork on a visible exterior bearing wall is a clear indication that deterioration has occurred and that the structural stability of the wall roof system is in question as well as the stability to conduct safe tactical interior or roof operations by fire service personnel.
Other age related conditions affecting bowstring truss stability include creep deformation, stressed, loosened or damaged connection points due to imposed loads over many decades, the effects on longer deflection under load, the effects or wood shrinkage and drying affecting the geometry and thus strength and stability of the truss, along with a higher potential for structural failure and collapse.
These conditions can all be exasperated by fire, heat impingement or contact as well as long term imposing dead loads of the roofing system(s) and more importantly live loads such as rain or snow accumulation (as well as concentrated live loads) or the placement of fire personnel to conduct tactical roof assignments. Published research and test results have shown that in many instances heritage vintage truss systems such as the bowstring truss (circa 1880-1950) were designed in a manner that did not take into account conservative bottom cord tensile strength design. Most trusses from this time frame were not designed under the same criteria implemented in today’s building codes and specifications and thus are prone to compromise and failure under a variety of both fire and non-fire induced incident scenarios.
Representative Construction Cut Away of a Heavy Timber Gable Truss Roof and Pilaster
Typical Bowstring Roof Truss Configuration and span
Bowstring Truss Profile
Another key observation point during operational assessment and size-up includes the observation of any excessive truss chord sag along the span, rot, deterioration, cracked or split chords, splices, web members of visible end connections. The identification of such conditions during any phases of operations such be promptly evaluated as a pronounced high risk to personnel safety and further operational integrity. In other words; it’s time to immediately reconsider risk, strategic and tactical operational objectives and the likelihood for isolated structural compromise or catastrophic structural collapse.
Various Wall Construction Features
The following video clips provide good examples of the extent, physical force and collective momentum of mass that a collapsing section of brick wall can inflict as it fails. These video clips represent multi-floor collapse and variabley larger collapse zones on grade and within the immediate operating areas.
Other Insights and Considerations
During all operations involving actual or suspected Bowstring Truss Roofing Support Systems Command and Company Officers should be sensitive to risk assessment indicators related to both fire induced conditions as well as environmental and age induced factors.
Pre-plan your buildings look at the construction, components, features and condition of the building; there is a tremendous amount of information out there. Understand and comprehend what to look for, what it is that you’re looking at and more importantly make sure the information is retrievable for on-scene application and that the information is utilized when formulating IAP and in the dynamic risk assessment process
During Dynamic Risk Assessment, special attention should be focused on Predicated Building Performance common to identified building systems, features and structural systems that are based upon Occupancy Performance and NOT Occupancy Type.
The Federal Emergency Management Agency’s (FEMA) United States Fire Administration (USFA) issued a special report examining the characteristics of fires in vacant residential buildings. The report, Vacant Residential Building Fires, was developed by USFA’s National Fire Data Center and provides useful insights and recommendations. Link HERE
When developing incident action plans and operational assignments at incidents involving possible Vacant, Unoccupied or Abandoned structures, command and company officers shall implement a formulative risk -benefit assessment consistent with departmental procedures, policies and expectations.
Be knowledgable of operational factors and considerations related to operations at Vacant, Unoccupied or Abandoned structures; HERE and HERE
Read the Newest NIOSH Alert: Preventing Deaths and Injuries of Fire Fighters at Structure Fires, HERE
Start considering building; age, deterioration, environmental impacts and influences in your IAP and tactical considerations, we at times forget to consider these performance indicators effectively during initial or sustained operations.
Learn more about Building Construction, Occupancy Profiling, Reading a Building, Occupancy Risk versus Occupancy Type and always consider Tactical Patience.
Increase your knowledge on Structural Collapse indicators especially for buildings of masonry construction in both Type III and Type IV construction.
There is a Predictability of Performance in all Buildings and Occupancies with Heavy Timber or Built-up Bowstring Truss Structural Systems; Know what they are.
Understand what to look for in Heavy Timber or Built-up Bowstring Truss Structural System integrity related to; Age and Deterioration, Gravity, Cross Grain Shrinkage, Wood Defects that are self-evident in chords and web members, Upper Chord Buckling, Lower Chord splitting or failure points, web splitting or pull-outs, multiple roofing systems or membranes, multiple void spaces, compromised bearing walls or pilasters, compromised or degraded bearing points or truss ends.
Learn to identify masonry wall features and what they mean towards tactical operations
These are some immediate considerations for increasing operational integrity while maintaining firefighter safety and and does not reflect the full extent of safety or operational considerations that must be imposed and implemented at operations involving buildings of Type III or IV construction or those with bowstring truss components; but it is a stepping stone and for many, the first exposure to this type of information.
Remember; Building Knowledge = Firefighter Safety
Other Links
Roof of building in deadly fire called ‘defective’ in 2007, Link HERE
A fire commissioner’s words on tragedy, tempered by his family history, HERE
Chicago Tribune Editorial: ”Every fireman knows”, a must read….HERE
Chicago fire personnel evacuate an injured firefighter at a extra-alarm fire at 1700 East 75th Street. (E. Jason Wambsgans/ Chicago Tribune)
From emerging published reports, Two Chicago firefighters died after a wall collapsed during a 3-11 alarm fire at an abandoned South Side commercial building this morning, authorities said. Fourteen other firefighters were injured, including two who were trapped with the ones who died.
Police squad cars escorted two ambulances north on Lake Shore Drive to Northwestern as ramps were closed to clear it of traffic, according to fire communications. One of the firefighters taken there has died, sources said. The condition of the other one was not known.
A third trapped firefighter was taken to Christ Medical Center in Oak Lawn, where he died. Late this morning, dozens of firefighters stood at attention, removing their caps and saluting, as the body of their fallen colleague was taken from the hospital and put in an ambulance. A police escort led the ambulance to the medical examiner’s office
The fourth firefighter buried in the rubble, and as many as 12 other firefighters with undisclosed injuries, were also taken to hospitals. Fire officials and sources said 10 were stable and six were taken to hospitals in serious to critical condition, including the two who later diedThe firefighters’ deaths came on the 100th anniversary of a huge fire at the Union Stockyards that claimed the life of 21 Chicago firefighters, the single greatest loss in U.S. history of professional big-city firefighters until Sept. 11, 2001.
A dozen or fewer firefighters were in the building when the roof above them collapsed, said Fire Department spokesman Larry Langford. Firefighters searched through rubble for more than an hour as four trapped firefighters were pulled out and rushed to hospitals.
“They worked hard, got them out fast,” said Fire Commissioner Robert Hoff at the scene.
He said the search was continued, with dozens of firefighters digging through rubble, because of the possibility that homeless people may have been in the building seeking shelter from the cold. Neighbors reported that squatters have been staying in the building, but no others were found in the rubble.
The fire broke out about 6:54 a.m. in the abandoned one-story brick building in the 1700 block of East 75th Street.
The fire was raised to two and then three alarms to save the trapped firefighters. A “mayday” was called. Firefighters also reported having problems with frozen hydrants.
Aerial View of the Buildings along 1700 East 75th Street
Informational Update- The two Chicago Firefighters have been identified;
FF Edward Stringer:
FF Corey Ankum:
According to published reports; Initial incident reports are that FF Stringer and FF Ankum had been on or near the roof of the building in the 1700 block of East 75th Street this morning with other Firefighters when it collapsed. The building had a bow string truss in the rear and a flat roof in front. 34-year-old Cory Ankum from Engine 72, had been on the department only sixteen months. Corey had previously served as a Chicago Police officer before joining the city’s fire department. His wife is Mayor Richard Daley’s personal secretary. He is a father of three children under 12 years old, including a one-year old child.
FF Edward Stringer, a 12-year veteran of the CFD and is reported to have several grown children and lives alone. Published sources are indicating, he was working as a “relief Lieutenant”, covering for another Lieutenant for an unknown reason .
Before Stringer went in with the hoseline, the normally-assigned Lieutenant showed up told him he could leave now. Stringer declined the offer, saying “I got it”, and went inside. The ensuing collapse killed him and Ankum.
CHICAGO FD TERMINOLOGY:
If you are unfamiliar with CFD terminology, procedures etc. BELOW is an excellent source for those details:
Firefighters and friends stand at attention as an ambulance carrying the body of Corey Ankum leaves Christ Medical Center in Oak Lawn for the Cook County medical examiner’s office. (Zbigniew Bzdak/Tribune)
Latest posted reports state Seventeen (17) Firefighters were injured: HERE
UL Ventilation and Fire Behavior Full Scale Testing
Impact of Ventilation on Fire Behavior in Legacy and Contemporary Residential Construction
For many of you that have been following my writings and perspectives on building construction, firefighting, command risk management and operational excellence for firefighter safety have long recognized that I have been promoting and advocating the fact the fireground is changining, our stratgies and tactics demand change adn does the demand for increased knowledge within the areas of building construction, fire dynamics, while integrating the art and science of firefighting. The most recent release of the testing report from Underwriters Laboratories; Impact of Ventilation on Fire Behavior in Legacy and Contemporary Residential Construction and the accompaning emphirical data further validates assumptions and presmises that many of us shared based upon field obervations and first hand incident operations related to the dramatic changes being witnessed as a result of operational challenges in a wide varity of occupanies and building types. This material is a must read for all emerging and practicing company and command officers ( for starters) to being grasping the magnitude and extent of quantifiable data that supports the premise that combat fire engagement and suppression operations and the rules of engagement are going to change and that change is fast approaching. Considerations for Tactical Patience and Adaptive Fireground Management are continued themes I will expand upon in future postings….
Here’s the executive summary of the report and findings from UL. For an download of the entire UL Report, go HERE.
Under the United States Department of Homeland Security (DHS) Assistance to Firefighter Grant Program, Underwriters Laboratories examined fire service ventilation practices as well as the impact of changes in modern house geometries. There has been a steady change in the residential fire environment over the past several decades. These changes include larger homes, more open floor plans and volumes and increased synthetic fuel loads. This series of experiments examine this change in fire behavior and the impact on firefighter ventilation tactics. This fire research project developed the empirical data that is needed to quantify the fire behavior associated with these scenarios and result in immediately developing the necessary firefighting ventilation practices to reduce firefighter death and injury.
Two houses were constructed in the large fire facility of Underwriters Laboratories in Northbrook, IL. The first of two houses constructed was a one-story, 1200 ft2, 3 bedroom, 1 bathroom house with 8 total rooms. The second house was a two-story 3200 ft2, 4 bedroom, 2.5 bathroom house with 12 total rooms. The second house featured a modern open floor plan, two-story great room and open foyer. Fifteen experiments were conducted varying the ventilation locations and the number of ventilation openings. Ventilation scenarios included ventilating the front door only, opening the front door and a window near and remote from the seat of the fire, opening a window only and ventilating a higher opening in the two-story house. One scenario in each house was conducted in triplicate to examine repeatability.
The results of these experiments provide knowledge for the fire service for them to examine their thought processes, standard operating procedures and training content. Several tactical considerations were developed utilizing the data from the experiments to provide specific examples of changes that can be adopted based on a departments current strategies and tactics.
Under the United States Department of Homeland Security (DHS) Assistance to Firefighter Grant Program, Underwriters Laboratories examined fire service ventilation practices as well as the impact of changes in modern house geometries.
There has been a steady change in the residential fire environment over the past several decades. These changes include larger homes, more open floor plans and volumes and increased synthetic fuel loads. This series of experiments examine this change in fire behavior and the impact on firefighter ventilation tactics.
This fire research project developed the empirical data that is needed to quantify the fire behavior associated with these scenarios and result in immediately developing the necessary firefighting ventilation practices to reduce firefighter death and injury.
Two houses were constructed in the large fire facility of Underwriters Laboratories in Northbrook, IL.
The first of two houses constructed was a one-story, 1200 ft2, 3 bedroom, 1 bathroom house with 8 total rooms.
The second house was a two-story 3200 ft2, 4 bedroom, and 2.5 bathroom house with 12 total rooms.
The second house featured a modern open floor plan, two story great room and open foyer.
Fifteen experiments were conducted varying the ventilation locations and the number of ventilation openings. Ventilation scenarios included ventilating the front door only, opening the front door and a window near and remote from the seat of the fire, opening a window only and ventilating a higher opening in the two-story house.
One scenario in each house was conducted in triplicate to examine repeatability. The results of these experiments provide knowledge for the fire service for them to examine their thought processes, standard operating procedures and training content. Several tactical considerations were developed utilizing the data from the experiments to provide specific examples of changes that can be adopted based on a departments current strategies and tactics.
The tactical considerations addressed include:
Stages of fire development: The stages of fire development change when a fire becomes ventilation limited.
It is common with today’s fire environment to have a decay period prior to flashover which emphasizes the importance of ventilation.
Forcing the front door is ventilation:Forcing entry has to be thought of as ventilation as well.
While forcing entry is necessary to fight the fire it must also trigger the thought that air is being fed to the fire and the clock is ticking before either the fire gets extinguished or it grows until an untenable condition exists jeopardizing the safety of everyone in the structure.
No smoke showing: A common event during the experiments was that once the fire became ventilation limited the smoke being forced out of the gaps of the houses greatly diminished or stopped all together.
No some showing during size-up should increase awareness of the potential conditions inside.
Coordination: If you add air to the fire and don’t apply water in the appropriate time frame the fire gets larger and safety decreases.
Examining the times to untenability gives the best case scenario of how coordinated the attack needs to be.
Taking the average time for every experiment from the time of ventilation to the time of the onset of firefighter untenability conditions yields 100 seconds for the one-story house and 200 seconds for the two-story house
In many of the experiments from the onset of firefighter untenability until flashover was less than 10 seconds.
These times should be treated as being very conservative. If a vent location already exists because the homeowner left a window or door open then the fire is going to respond faster to additional ventilation opening because the temperatures in the house are going to be higher.
Coordination of fire attack crew is essential for a positive outcome in today’s fire environment.
Smoke tunneling and rapid air movement through the front door: Once the front door is opened attention should be given to the flow through the front door.
A rapid in rush of air or a tunneling effect could indicate a ventilation limited fire.
Vent Enter Search (VES): During a VES operation, primary importance should be given to closing the door to the room.
This eliminates the impact of the open vent and increases tenability for potential occupants and firefighters while the smoke ventilates from the now isolated room.
Flow paths:Every new ventilation opening provides a new flow path to the fire and vice versa.
This could create very dangerous conditions when there is a ventilation limited fire.
Can you vent enough?: In the experiments where multiple ventilation locations were made it was not possible to create fuel limited fires.
The fire responded to all the additional air provided.
That means that even with a ventilation location open the fire is still ventilation limited and will respond just as fast or faster to any additional air.
It is more likely that the fire will respond faster because the already open ventilation location is allowing the fire to maintain a higher temperature than if everything was closed. In these cases rapid fire progression if highly probable and coordination of fire attack with ventilation is paramount.
Impact of shut door on occupant tenability and firefighter tenability: Conditions in every experiment for the closed bedroom remained tenable for temperature and oxygen concentration thresholds.
This means that the act of closing a door between the occupant and the fire or a firefighter and the fire can increase the chance of survivability.
During firefighter operations if a firefighter is searching ahead of a hoseline or becomes separated from his crew and conditions deteriorate then a good choice of actions would be to get in a room with a closed door until the fire is knocked down or escape out of the room’s window with more time provided by the closed door
Potential impact of open vent already on flashover time: All of these experiments were designed to examine the first ventilation actions by an arriving crew when there are no ventilation openings.
It is possible that the fire will fail a window prior to fire department arrival or that a door or window was left open by the occupant while exiting.
It is important to understand that an already open ventilation location is providing air to the fire, allowing it to sustain or grow.
Pushing fire: There were no temperature spikes in any of the rooms, especially the rooms adjacent to the fire room when water was applied from the outside. It appears that in most cases the fire was slowed down by the water application and that external water application had no negative impacts to occupant survivability.
While the fog stream “pushed” steam along the flow path there was no fire “pushed”.
No damage to surrounding rooms: Just as the fire triangle depicts, fire needs oxygen to burn.
A condition that existed in every experiment was that the fire (living room or family room) grew until oxygen was reduced below levels to sustain it.
This means that it decreased the oxygen in the entire house by lowering the oxygen in surrounding rooms and the more remote bedrooms until combustion was not possible.
In most cases surrounding rooms such as the dining room and kitchen had no fire in them even when the fire room was fully involved in flames and was ventilating out of the structure.
Online Training Program
In order to make the results of this study more user friendly for the fire service to examine, UL developed an online interactive training module that can be viewed by clicking here. The program includes a professionally narrated description of all of the experiments, their results and the tactical considerations. Experimental video is used and graphical data is explained in a way that brings science to the street level firefighter.
UL University On-Line CBT
Comparison of Modern and Legacy Home Furnishings
An experiment was conducted with two side by side living room fires. The purpose was to gain knowledge on the difference between modern and legacy furnishings. The rooms measured 12 ft by 12 ft, with an 8 ft ceiling and had an 8 ft wide by 7 ft tall opening on the front wall. Both rooms contained similar amounts of like furnishings.
The modern room was lined with a layer of ½ inch painted gypsum board and the floor was covered with carpet and padding.
The furnishings included a microfiber covered polyurethane foam filled sectional sofa, engineered wood coffee table, end table, television stand and book case.
The sofa had a polyester throw placed on its right side. The end table had a lamp with polyester shade on top of it and a wicker basket inside it.
The coffee table had six color magazines, a television remote and a synthetic plant on it.
The television stand had a color magazine and a 37 inch flat panel television.
The book case had two small plastic bins, two picture frames and two glass vases on it.
The right rear corner of the room had a plastic toy bin, a plastic toy tub and four stuffed toys.
The rear wall had polyester curtains hanging from a metal rod and the side walls had wood framed pictures hung on them.
The legacy room was lined with a layer of ½ inch painted cement board and the floor was covered with unfinished hardwood flooring.
The furnishings included a cotton covered, cotton batting filled sectional sofa, solid wood coffee table, two end tables, and television stand.
The sofa had a cotton throw placed on its right side.
Both end tables had a lamp with polyester shade on top of them.
The one on the left side of the sofa had two paperback books on it.
A wicker basket was located on the floor in front of the right side of the sofa at the floor level.
The coffee table had three hard-covered books, a television remote and a synthetic plant on it.
The television stand had a 27 inch tube television.
The right front corner of the room had a wood toy bin, and multiple wood toys.
The rear wall had cotton curtains hanging from a metal rod and the side walls had wood framed pictures hung on them.
Both rooms were ignited by placing a lit stick candle on the right side of the sofa. The fires were allowed to grow until flashover. The modern room transitioned to flashover in 3 minutes and 30 seconds and the legacy room at 29 minutes and 30 seconds.
Fire suppression operations on Alpha side prior to collapse. Firefighter is seen in the immediate collapse zone
The NIOSH Fire fighter Investigation and Prevention Program, Fire Fighter Fatality Investigation Reports recently released Report # F2009-12 for a Near-Miss event that seriously injured a firefighter wih significant learnings; HERE
Through the Fire Fighter Fatality Investigation and Prevention Program, NIOSH conducts investigations of fire fighter line-of-duty deaths to formulate recommendations for preventing future deaths and injuries. The program does not seek to determine fault or place blame on fire departments or individual fire fighters, but to learn from these tragic events and prevent future similar events.
On May 21, 2009, a 36-year-old male career fire fighter was seriously injured while operating in a non-designated collapse zone of a commercial structure when an overhang of a bowstring truss roof system collapsed and struck him. The first arriving company officer reported a working fire in a single story Type II warehouse.
The officer looked under a steel roll-up door that was raised approximately three feet off of the ground and saw heavy fire towards the rear of the structure from floor to ceiling. Per department procedures, the first arriving companies went into a “Fast Attack” mode. Crews attempted but were unable to enter the structure because the steel roll-up door wasn’t functioning and the man door was heavily secured.
The department’s Deputy Chief arrived on the scene 9 minutes after the initial crew and determined that the fire should be fought defensively, however, this command was not relayed over the radio or verified with all crews. A crew was operating a 2 ½-inch handline just outside the structure approximately 20 minutes after the first apparatus arrived when the overhang collapsed and trapped the nozzleman.
Key contributing factors identified in this investigation include:
scene management and risk analysis,
a well-involved fire in a structure with hazardous construction features, and
fire fighters operating within a potential collapse area.
STRUCTURE
The building was constructed in 1954 and was a single-story warehouse of Type IV construction. The dimensions of the building were 110 feet deep by 50 feet wide, covering approximately 5,500 square feet. The height of the building was approximately 20 feet. The occupancy use of the building was commercial and it operated as a warehouse. The building’s structural system consisted of masonry block bearing walls with four heavy timber wood bowstring trusses for a roof system.
The heavy timber wood trusses had a 50-foot clear span to the bearing walls and were located 19 feet 9 inches on center. The heavy timber wood truss assemblies were 48 feet 7 inches in depth and were constructed of 4-inch x 6-inch timber cords and webs connected with bolt fasteners with a metal splice plate and bolt configuration at the bottom chord span. Solid 2-inch x 10-inch wood purlins located on 24-inch centering spanned perpendicular to the truss assembly with a ¾-inch plywood roofing deck. The roofing system assembly was exposed and did not have a membrane or other passive fire protection features.
Aerial view of Building
Structural stability to the heavy timber truss units was provided by 2-inch x 6-inch wood cross bracing in conjunction with the stability provided by the wood purlins and plywood deck roofing membrane. The structure contained six skylights that were 3 feet by 6 feet .
The overall integrity and structural stability of this type of structural support and roofing system is contingent upon all components maintaining their connections and load bearing or load transferring capacity.
The A-side was a non-load bearing wall that showed the traditional arched roof profile that is consistent with bowstring roof construction. The A-side wall also consisted of what appeared to be an overhanging or cantilevered façade that was covered by stucco. The overhang was part of the original construction that tied back into the bowstring truss system. The fire building was integrated into a block of commercial occupancies so that only the A-side was accessible for interior fire fighting activities.
The B-side exposure of the building was adjacent to a parking lot and was of masonry construction without any windows or doors. The C-side and D-side exposures were of similar size and construction and shared party walls between their respective sides. A pre-plan had not been completed for this structure.
Similar Interior Construction Features
At the time of the fire, the building was used as a place to grow marijuana illegally. The man door was heavily barricaded and a false wall was constructed to shield the operations from the exterior when the roll-up door was lifted. The electric service was severed and rerouted to circumvent the electric meter in order to conceal the operations.
TRAINING and EXPERIENCE
The state requires all career fire fighters to complete training equivalent to NFPA, 1001 Standard for Fire Fighter Professional Qualifications, Fire Fighter 1. The department provides up to 17 months of training to certify fire fighters to NFPA Fire Fighter 1 and 2 qualifications, and a one year probationary period of supervised training for department fire fighter certification. The additional training during this probationary time focuses on driver training, pump operations, aerial ladder operations, and specialized equipment training.
Alpha Side
Injured Fire Fighter
The injured fire fighter had more than six years of experience and had completed department provided classroom/field training on topics such as: live fire training, rapid intervention crew (RIC) procedures, and hazardous materials.
Initial Incident Commander (IC)
The first due company officer had more than 15 years of experience with the department. Six of those years were as a fire fighter, seven years as a cross-trained paramedic, and 18 months as a lieutenant in an acting and permanent appointment at the time of the incident. The initial IC had completed the department provided five four-day sessions on critical fireground topics that were required for newly appointed lieutenants. This training included the following topics: building construction, incident management system (IMS), size-up, company operations, and rapid intervention company (RIC) operations.
Incident Commander (IC)
The IC had more than 30 years of experience and had completed department provided classroom/field training in topics such as: health and safety 1, 2, 3 & 4; fire command; fire instructor; fire investigation; fire management; fire officer; fire prevention; incident command; incident safety officer; and RIC procedures.
Incident Safety Officer (ISO)
The battalion chief who was assigned as the ISO for this incident had more than 20 years of experience and had completed department provided classroom/field training in topics such as: health and safety 1,2,3,and 4; fire command; fire instructor; RIC procedures; hazardous materials; heavy rescue 1 and 2; training officer development; wildland training; and emergency vehicle operations.
INVESTIGATION INSIGHTS
At 0446 hours central dispatch received an alarm for a reported structure fire with fire and smoke showing at a commercial occupancy. Engine 42 (E42) was the first apparatus on the scene at 0449 hours and the officer reported on the radio a working fire in a single story Type II warehouse. Note: The classification of Type II was incorrect. This building was a Type IV construction due to the heavy timber bowstring trusses.
The E42 Lieutenant and a fire fighter ran to a steel garage roll-up door that was raised approximately three feet off of the ground on the left of the A-side wall. The E42 Lieutenant looked under the door and saw heavy fire towards the rear of the structure from floor to ceiling. The E42 Lieutenant and the fire fighter attempted to raise the door but could not due to the door being dislodged from its track. Note: The door frame had been compromised by the fire and the tracks were not attached to the wall. They immediately went to a man door to the right of the A-side. It was locked and had heavy security bars. The E42 Lieutenant called Battalion Chief 6 for a truck company to perform forcible entry.
The E42 Lieutenant ordered the crew to prepare the multiversal, which is a master stream appliance that can be used on the ground, and 2 ½-inch handlines to attempt to attack the fire through the roll-up door. Note: Per department policy, all first arriving companies and officers go to work in a “fast attack” mode. At approximately 0452 hours Engine 32 (E32) and Engine 17 (E17) pulled onto the road leading to the structure within a block from the structure.
Both the E32 and E17 officers immediately radioed dispatch and requested a second alarm due to the heavy fire self-venting from the roof of the structure. E32 proceeded to the front of the structure, dropped off two 3-inch supply lines for E42, and went to hook up to a hydrant to supply E42. E32 used a 10-foot section of 3-inch supply line to hook up to one side of the hydrant. They used another 50-foot section of 3-inch supply line to hook up to the other side of the hydrant.
During this same time, at approximately 0452 hours, BC6 arrived on the scene, called to ensure a second alarm, and conducted a size-up of the front of the building and the operations taking place. A division chief arrived on the scene at 0453 hours, assumed incident command (IC), and ordered BC6 to protect Exposure D. The E17 officer and fire fighters [including the injured fire fighter (IFF)] walked up to the front of the structure and saw the E42 and E32 crews attempting to deploy the multiversal and two 2 ½-inch handlines off of E42. Note: The crews were having difficulty due to having to assemble the three 50-foot sections of 2 ½-handlines from a bag stored on top of each apparatus. The crew also removed the multiversal from on top of E42 and placed it on the ground for operation.
The IFF took the nozzle of one of the 2 ½-inch handlines and was backed up by an E17 fire fighter. Two additional fire fighters manned the other 2 ½-inch handline and were protecting the D-exposure by shooting water onto the roof from over 20 feet away from the structure. The E17 officer and E17 fire fighter operated the multiversal over 20 feet back from the roll-up door and attempted to shoot water through the opening where the door had pulled away from the wall. The E17 officer noticed that both handlines were ineffective and he went to check on the IFF. The IFF’s handline stream was ricocheting off of the man door and the four windows above it.
The L7 crew had assembled handtools on the ground in front of the Command Post. The E17 officer took a saw to the man door in an attempt to open it so that the handline could be effective. He quickly determined that the saw would not work due to the door being so heavily protected. Battalion Chief 09 arrived on the scene at 0500 hours and was designated by the IC as the Incident Safety Officer (ISO) at approximately 0504 hours. He instructed the E17 officer to attempt to open the door with a rabbit tool; the E17 officer informed the ISO he wasn’t sure where the truck company kept it. Immediately after, BC6 ordered the E17 officer to take his saw to the roll-up door and cut an opening for access.
He cut a three foot by six foot hole in the door and was attempting to cut across the door when he was tapped on the shoulder by the Deputy Chief which he assumed meant he was to quit. During this time, BC6 had received orders from the Deputy Chief to pull everyone back from the front of the building and to ensure that no one went inside. Note: According to interviews conducted by NIOSH investigators, this is the first time that anyone on the scene communicated the need to go defensive to the initial arriving officers. It was reported to the NIOSH investigators that every officer who reported to the command post was given face-to-face directions that the fire was defensive and that no one was to enter the building. This tactical decision was not relayed over the radio.
BC6 ordered the crews from E42 and E17 to set up and direct a master stream into the hole through the roll-up door from a distance. The crews fought fire from a distance with the master stream for several minutes. The IFF and the E17 fire fighter continued to fight fire with the handline moving from the roll-up door to the man door several times. Note: This crew, along with many other members that were interviewed, reported not receiving any orders regarding a defensive operation.
BC6 noticed that the fire had compromised an electrical weather head and that the power lines were going to come down soon. He turned to order crews to vacate the area where the power lines would possibly fall when he heard a large crash. He turned back and saw that the roof overhang had fallen onto the sidewalk. The collapse trapped the IFF who was operating the handline into the windows along with the E17 fire fighter. Members immediately rushed to the scene to rescue the trapped fire fighter.
The IC ordered BC6 to command the rescue crew and complete a personnel accountability report (PAR) for the fireground.
A full PAR was completed and the trapped fire fighter was removed and transported to a local hospital.
Collapse into the street on Alpha Side
NIOSH investigators concluded that, to minimize the risk of similar occurrences, fire departments should:
ensure that they have consistent policies and training on an incident management system
develop, implement and enforce written standard operating procedures (SOPs) that identify incident management training standards and requirements for members expected to serve in command roles
ensure that the incident commander conducts an initial size-up and risk assessment of the incident scene before beginning fire fighting operations
ensure that the first due company officer establishes a stationary command post, maintains the role of director of fireground operations, and does not become involved in firefighting efforts
implement and enforce written standard operating procedures (SOPs) that define a defensive strategy
ensure that policies are followed to establish and monitor a collapse zone when conditions indicate the potential for structural collapse
train all fire fighting personnel on building construction and the risks and hazards related to structural collapse
conduct pre-incident planning inspections of buildings within their jurisdictions to facilitate development of safe fireground strategies and tactics
NIOSH RECOMMENDATIONS
Recommendation #1: Fire departments should ensure that they have consistent policies and training on an incident management system.
Recommendation #2: Fire departments should develop, implement and enforce written standard operating procedures (SOPs) that identify incident management training standards and requirements for members expected to serve in command roles
Recommendation #3: Fire departments should ensure that the incident commander conducts an initial size-up and risk assessment of the incident scene before beginning fire fighting operations
Recommendation #4: Fire departments should ensure that the first due company officer establishes a stationary command post, maintains the role of director of fireground operations, and does not become involved in firefighting efforts.
Recommendation #5: Fire departments should develop, implement and enforce written standard operating procedures that define defensive fire fighting operations.
Recommendation #6: Fire departments should ensure that policies are followed to establish and monitor a collapse zone when conditions indicate the potential for structural collapse.
Recommendation #7: Fire departments should train all fire fighting personnel in building construction and in the risks and hazards related to structural collapse.
Recommendation #8: Fire departments should conduct pre-incident planning inspections of buildings within their jurisdictions to facilitate development of safe fireground strategies and tactics.
Discussion: NFPA 1620 Standard for Pre-Incident Planning, states “The purpose of this document shall be to develop pre-incident plans to assist responding personnel in effectively managing emergencies for the protection of occupants, responding personnel, property, and the environment.” A pre-incident plan identifies deviations from normal operations and can be complex and formal, or simply a notation about a particular problem such as the presence of flammable liquids, explosive hazards, modifications to structural building components, or structural damage from a previous fire.
Building characteristics including type (or more importantly risk) of construction, materials used, occupancy, fuel load, roof and floor design, and unusual or distinguishing characteristics should be recorded, shared with other departments who provide mutual aid, and if possible, entered into the dispatcher’s computer so that the information is readily available if an incident is reported at the noted address.
Since many fire departments have tens and hundreds of thousands of structures within their jurisdiction, it is a challenge to establish an effective preplanning system. Priority should be given to those having elevated or unusual fire hazards and life safety considerations.
One tool for fire departments to use in assessing their risks for structures within their jurisdictions is the mnemonic, BECOME SAFE: (HERE)
Building
Evaluation
Construction/occupancy
Operational hazards
Manage time and elements
Engagement
Situational awareness
Assessment and risk analysis
Fire behavior and effects
Evaluate and execute
BECOME SAFE by CJ Naum
In this incident, the presence of the bowstring truss presented an elevated life safety consideration in the event of a fire. A thorough building inspection and pre-incident plan for a single-story, bowstring truss occupancy in this area could have potentially identified the hazards typically associated with this type of construction such as: ceiling voids, fuel loads, non-permitted renovations, roof construction, HVAC location, and exit locations. Evaluating the construction features and layout of the structure allows the fire department the opportunity to determine a response protocol for the specific identified hazards and to develop fireground strategies and tactics (ventilation strategies, avenues of fire spread, proper attack line selection, etc.) before an incident occurs.
The construction features of occupancy (bowstring truss), possible commercial fuel loads and access restrictions suggested large volumes of water would be necessary to fight a major fire at the site. A more complete pre-planning process, involving individual fire companies within their response territory could have noted this information which may have aided the IC in developing a safer and more effective offensive or defensive strategy. In order to facilitate open communication, fire department personnel and building code officials should be cross-trained on each-others’ duties and responsibilities.
Fire fighters should have a basic understanding of what a code violation is and how to report them during a pre-plan, and building code inspectors should have a basic understanding of fire fighter safety issues during their inspections. The relay of this information could be used to facilitate dynamic risk management and enhanced command and control.
See Report Insights related to Bowstring Truss Roof Operations on the FDNY Waldbaum’s Fire August 1978;HERE
Description: This clip discusses the hazards and lessons learned from fighting fires in modular construction homes.
This link comes by way of Chief Kevin A. Gallagher of the Acushnet (MA) Fire & EMS Department and our good friends at NFFF/Everyone Goes Home Program. This is a great new program on FF Safety, Operational Excellence and understanding the newest challenges on modular residential construction….
Do you know what's underneath you as you're making entry?
If you’ve been paying attention to the latest news and on the job reports these past few days, you may have noticed there’s been an emerging trend evident in near miss, close-calls resulting in maydays, RIT deployments and self-rescue resulting from floor compromise and floor collapse.
As I was doing some research and posting links related to the first one or two events on Buildingsonfire on Facebook, HERE, it became evident that there was an immediate opportunity to get some learning’s and insights out. If you have a chance head over to Facebook and link into Buildingsonfire and check out the incident links posted as well as some immediate report links.
I’ll plan to develop some operational safety and awareness insights related to building construction, floor systems and operational integrity in the next few days. I’ll get a comprehensive list of events and incident parameters compiled and posted also.
In the meantime here are some links I pulled together that you should take the time to read and share with your companies, personnel and staff…..
This seems like a good time to have a ten minute drill on these events as Operating Expeeince (OE) on floor systems and operational safety.
Reference Links for Operational Insights and Operating Experience (OE)
Here’s some screen shots from Buildingsonfire on Facebook. Go HERE or follow the link at the left column. Join the growing list of 3500 fans with Buildingsonfire on Facebook and Buildingsonfire.com (fully launching in January, 2011)
Taking it to the Streets: Looking Forward Through the Rear View Mirror
On Your Street, In Your City, Across the Country, Around the WorldTM
Join us on Wednesday night December 15th at 9:00 pm EST for an insightful look back at 2010 and forward into 2011 and beyond with a stellar line-up of fire service leaders.
Grab a cup of coffee and sit down for a special two part, two hour program with Taking it to the Streets on Firefighernetcast.com where we’ll be Looking Forward Through the Rear View Mirror with Christopher Naum and this outstanding group of fire officers, fire service leaders and visionaries.
Join in on the live open discussion with fire service personnel from around the country. Check out the latest downloads of recent programs in the archives by visiting Taking it to the Street’s webpage on Firefighternetcast.com or for program insights at CommandSafety.com.
Tune in to the Program Wednesday evening December 15th at 9:00 pm EST, HERE
Training Program Download Compliments of Chris Naum
Operational Safety Considerations at Ordinary and Heavy Timber Constructed Occupancies
Building Type III and IV Training Materials for the Fire Service
This program was developed to support the case study information published within the 2009 Near-Miss Reporting Calendar for the Month of May, 2009 for the National Firefighter Near-Miss Reporting System. If you’re not familiar with the NFFNMRS, go to their web site, HERE for insights on resources and timely operational and training information, data and resources. The National Fire Fighter Near-Miss Reporting System is a voluntary, confidential, non-punitive and secure reporting system with the goal of improving fire fighter safety.
The Near-Miss Reporting System Report Case Study #08-0099 provided various insights into operational and safety issues affecting incident operations within a complex of warehouses built within the late 1800’s.
The program objectives consist of;
Increasing awareness of Type III and Type IV construction characteristics.
Provide awareness of inherent building construction, stability, performance and collapse considerations.
Provide a focus on Type III and Type IV building construction predominant in pre-1960 construction and occupancies.
Although Type III and IV construction is utilized in a variety of present day construction projects, these areas are excluded due to production limitations and focus on the near-miss case study reporting correlations.
This program provides an awareness level perspective on selective construction, operational and safety issues affecting the fire service, and does not represent other numerous areas of considerations. Formal training courses within a number of related subject areas is encouraged to increase knowledge and skill sets necessary to further strategic and tactical firefighting operations and incident management.
Resources:
National Firefighter Near-Miss Reporting System Operational Safety Considerations at Ordinary and Heavy Timber Constructed Occupancies PowerPoint Program developed by Christopher Naum,HERE
Today December 3, 2010 marks the 11th anniversary of the Worcester Cold Storage Warehouse fire that resulted in the line of duty death of six courages brother firefighters.
For those of you who remember this event, take the time to reflect and honor the sacrifice made this day; to those of you who have not heard about the fire before- take the time to learn about the incident, the firefighters, the building, the operational factors and challenges, the courage, fortitude and convictions that define the American Fire Service, it’s honor, tradition and brotherhood.
The Worcester Six;
Firefighter Paul Brotherton Rescue 1
Firefighter Jeremiah Lucey Rescue 1
Lieutenant Thomas Spencer Ladder 2
Firefighter Timothy Jackson Ladder 2
Firefighter James Lyons Engine 3
Firefighter Joseph McGuirk Engine
On Friday, December 3, 1999, at 1813 hours, the Worcester, Massachusetts Fire Department dispatched Box 1438 for 266 Franklin Street, the Worcester Cold Storage and Warehouse Co. A motorist had spotted smoke coming from the roof while driving on an adjacent elevated highway. The original building was constructed in 1906, contained another 43,000 square feet. Both were 6 stories above grade. The building was known to be abandoned for over 10 years.
Due to these and other factors, the responding District Chief ordered a second alarm within 4 minutes of the initial dispatch. The first alarm assignment brought 30 firefighters and officers and 7 pieces of apparatus to the scene. The second provided an additional 12 men and 3 trucks as well as a Deputy Chief. Firefighters encountered a light smoke condition throughout the warehouse, and crews found a large fire in the former office area of the second floor. An aggressive interior attack was started within the second floor and ventilation was conducted on the roof. There were no windows or other openings in the warehousing space above the second floor.
Eleven minutes into the fire, the owner of the abutting Kenmore Diner advised fire operations of two homeless people who might be living in the warehouse. The rescue company, having divided into two crews, started a building search. Some 22 minutes later the rescue crew searching down from the roof became lost in the vast dark spaces of the fifth floor. They were running low on air and called for help. Interior conditions were deteriorating rapidly despite efforts to extinguish the blaze, and visibility was nearly lost on the upper floors. Investigators have placed these two firefighters over 150 feet from the only available exit.
Copywrite 1999 Roger B. Conant All Rights Reserved
An extensive search was conducted by Worcester Fire crews through the third and fourth alarms. Suppression efforts continued to be ineffective against huge volumes of petroleum based materials, and ultimately two more crews became disoriented on the upper floors and were unable to escape. When the evacuation order was given one hour and forty-five minutes into the event, five firefighters and one officer were missing. None survived.
A subsequent exterior attack was set up and lasted for over 20 hours utilizing aerial pieces and deluge guns from Worcester and neighboring departments. Task force groups from across the State of Massachusetts responded to initial suppression and subsequent recovery efforts. During this time, the four upper floors collapsed onto the second which became known as “the deck”. Over 6 million gallons of water were used during the suppression efforts.
According to NFPA records, this is the first loss of six firefighters in a structure fire where neither building collapse nor an explosion was a contributing factor to the fatalities.
Fireground Operations
KEY ISSUES
Abandoned building left unprotected and unsecured.
The failure to properly secure and maintain security at this warehouse allowed vagrants to enter, live in, and cause a fire in the building.
The lack of detection and suppression systems allowed the fire to grow unrestrained until discovered from the outside.
No barriers to prevent the spread of fire and smoke in a large space.
Despite some floors having over 15,000 square feet of storage space, there were no rated fire walls, functioning fire doors, or even an interior finish that would help limit fire growth and the spread of heat and smoke.
Fire spread via combustible interior finishes.
Being a cold storage warehouse, many walls and ceilings were covered with a combustible insulation material including cork, tar, expanded polystyrene foam, and sprayed-on polyurethane foam.
Delayed fire reporting
The building occupants left the warehouse without notifying authorities, and the fire was reported by passing motorists who observed smoke venting from the roof.
The absence of uncovered windows also prevented earlier detection from the exterior.
Access limitations for fire suppression and rescue.
Building construction featured a single staircase from the basement to the roof. This vertical opening was the only way to move through all levels and was congested with men and equipment from the start of operations.
The storage areas of the warehouse had no windows. These two factors left firefighters above the first floor without a secondary escape route and prevented ladder and rescue operations through windows.
Unusually long interior travel distances.
Firefighters had to crawl over 200 feet through heavy smoke from the single staircase to conduct a proper search.
Most lifelines were only 50 foot and SCBA air was limited to 30 minutes.
Searches and rescue operations were ineffective under these circumstances.
Exterior Circa 1998
BUILDING HISTORY AND CONSTRUCTION
The Worcester Cold Storage and Warehouse building was a six story structure at 266 Franklin Street in the heart of Worcester’s former warehousing and cold storage district. In the first half of the 21st century, cold storage was vital to the preservation and delivery of food before refrigerators became commonplace in American kitchens. The location was ideal with rail service provided by the former Boston and Albany Railroad which had a siding against the south end of the warehouse.
Even after the post-WWII decline in railroads, truck traffic was easily accommodated over nearby roads and later on the abutting Interstate 290 which was built in the late 1960’s.
The original warehouse (called “A-building” in previous reports) was constructed in 1906, faced due north onto Franklin Street and bordered Arctic Street to the east. There were six storage levels as well as a basement. The building measured 88 feet by 88 feet and had over 7,000 square feet of floor space on each level. The warehouse had an approximate exterior height of 80 feet.
An addition (called “B-building”) was constructed in 1912 against the west wall of A-building and measured 72 feet by 120 feet on the third floor and above. The 72 foot wall faced Franklin Street. The first and second floors were 88 foot and 101 foot deep respectively to accommodate railroad sidings and other structures on the southern on “C” side. Other investigations have referred to the former western exterior wall of A-building as “the fire wall” but there is no indication that this was a planned function. At least one opening was cut through this party wall on each level to access the new addition. B-building provided an additional 7,000 square feet of storage on the third floor and over 8,000 on floors four through six.
The Worcester Cold Storage complex involved additional structures to the south, but these were physically separate buildings and were not involved in this incident. The known openings between the warehouse and the southern structures were for utilities and refrigerants. The only effect was to block aerial access from the south during the fire.
Construction methods appear to be the same in both A and B buildings.
Exterior walls were 18 inches thick and consisted of brick and mortar. Interior floors on the first and second levels were poured concrete and were supported by cast iron columns.
The concrete was covered with carpet or asbestos tile where appropriate for use.
Upper floors were of heavy timber construction with 12 foot long 4 inch by 12 inch wood joists (16 inch o.c.) resting in pockets in the east and west brick exterior walls and attached to 16 inch by 16 inch wood girders on the inside.
The girders were on 12 foot centers and rested on 16 inch by 16 inch wood columns which were spaced 12 feet apart in both dimensions.
Flooring consisted of two layers of tongue and groove hardwood with some areas having an additional layer of 3/8 inch diamond plate.
Ceilings on individual floors varied from open joists in storage areas to be a suspended ceiling in the office area on the second floor.
Photographs taken prior to the fire suggest that some sections also had “glass board” as a finished surface. The exact make up of this material has not been determined.
No documentation was made of ceiling heights within the warehouse, but it appears they were approximately 11 foot throughout.
The roof was tar and gravel over a wood deck which covered a 4 foot tall cockloft above the sixth floor ceiling/roof assembly.
Roof penetrations included the stairway and elevator shaft on the east end of A-building and a skylight over the elevator shafts on B-building. An illuminated billboard sat on the roof of B-building and received power external to the warehouse structure.
NOTE: For the balance of this report the entire fire building will be referred to as the “warehouse” which consists of “A-building” on the east and “B-building” on the west. The A and B terminology was adopted early on in other investigations and should not be confused with fireground identifications of sides “A, B, C, & D”. In a large complex such as this, other terminology could have been created such as “Building 1”, “Building Z”, etc. (refer to the USFA Report for diagrams)
BUILDING USE
Worcester Cold Storage, a business, occupied the warehouse from 1906 until 1983 when it was sold to Chicago Dressed Beef. In 1987, CDB Realty Trust purchased the warehouse. CDB moved its operations to Millbrook Street in 1988 and shut down the refrigeration system in 1989 at which time the building was abandoned.
During its use, various petroleum based insulation materials were incorporated into the building including rigid expanded polystyrene boards and blown on polyurethane foam. These were applied to improve the temperature performance of the buildings Additionally, condensation along the exterior walls lead to the decay of some floor joists. Steel beams or angle brackets were added against the brick walls to pick up the floor load in several places.
Even to long term employees, the building was hard to navigate.
The upper four stories were almost identical, and some workers reported getting lost under the dim interior lighting conditions.
Condensation would cause ice to form around the ceiling fixtures, and this cone of ice would severely limit the amount of illumination.
There was no useful external light then or during the fire.
After it’s closing in 1989, the building was illegally entered on many occasions, resulting in vandalism, occupancy by homeless individuals, and a number of small “campfires.” At the time the fire occurred, there were no utility services in operation. Significant amounts of garbage and human wastes were scattered around the warehouse. The homeless woman involved in this incident said the interior smelled like a sewer.
VERTICAL PENETRATIONS
There were three stairways in the warehouse. Stairway 1 was in the northwest corner of B-building and went from the first floor (approximate street level) up to the second floor office area. Stairway 2 was located in the southern portion of B-building and went from the first floor to the third. It may have also accessed the basement. Stairway 3 was on the east side of A-building and ran from the basement to the roof. This was the only means of egress from the upper floors and was used heavily during the fire.
Two elevators were adjacent to stairway 3, and two more were adjacent to Stairway 2. At the time of the fire, all had been disabled, and the cars were in the basement. It is unknown if individual access doors were open or closed. The elevator shaft in B-building had a reinforced glass canopy at the roof level.
A 14 inch by 14 inch shaft penetrated the ceiling of the second floor office area and originally housed a 12 inch pipe for the ammonia recovery system.
This may have opened through all floors, and the presence of the pipe could not be confirmed.
HORIZONTAL PENETRATIONS
There was one opening on each level through the party wall dividing A-building from B-building. There were numerous doors and windows on the first floor, and several were forced open by firefighters to gain access. All windows on this level were secured with plywood to prevent entry. Windows on the second floor of B-building were limited to the office area in the northwest section and were also covered with plywood. There was a window on each of the second, third, and fourth floors in stairway 3 on the east side of A-building. A window opened into the adjacent elevator shaft on each of these floors also. All were blocked with plywood.
INTERIOR FINISH
Because the warehouse was used for cold storage, the insides of exterior walls and the roof were heavily insulated. Barriers between office space and freezer space were also heavily insulated. The original material of choice was cork which was impregnated or secured with tar. The thickness has been described from 6 inches to 18 inches depending on the location. Evidence was also found of additional layers of expanded polystyrene sheets and blown on polyurethane. In many places the finished surface was “glass board”. A recovered piece of this glass board was ignited by Worcester Fire personnel after this incident. The sample sustained combustion and gave off stringy black smoke not unlike pure styrene.
It was reported that all the interior partitions were made of corkboard, but it was probably a covering rather than a structural element. The office walls on the second floor were paneling installed over drywall. Many photographs of the cold storage areas taken before the fire show interior surfaces with a clean outer appearance consistent with the glass board. This would have provided a cleanable and wear resistant surface as opposed to bare cork or foam insulation.
INTERIOR LAYOUT
Since the fire did not extend to the basement or first floor, the layout of these spaces is less important. The first floor did, however, provide the access to the rest of the building for fire operations. All space above the first floor was used for cold storage or moving goods with the exception of the second floor office area on the northern half of B-building.
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