Dangers of Floor Collapse
Take the time to revisit two Firefighter LODD incidents that both occurred in the month of August in 2006 and 2009 respectively. Excerpts from the NIOSH Reports have been included that are part of the NIOSH FIRE FIGHTER FATALITY INVESTIGATION AND PREVENTION PROGRAM (HERE).
Both of these incidents involved a double firefighter line-of-duty death (LODD) and resulted from a floor collapse during the conduct of operations within the fire involved structures. There are numerous lessons learned and recommendations that can be considered and applied in organizations and agencies across the country, both large and small; career or volunteer.
These incidents bring to light the occupancy risks present in some of our most common of building occupancies, and continue to provide the basis for operational considerations and management based upon occupancy risk versus occupancy type. There are numerous operational considerations when addressing fires located in basement or underdeck areas and the subsequent management of those incidents based upon known or assumed building characteristics, occupancy risk and profile, inherent or presumed building stability and potential for structural compromise and the operational risk from isolated or catastrophic of collapse.
- Buffalo (NY) Fire Department: August 24, 2009
- FDNY: August 27, 2006
Some Other Links related to Floor Collapses and Reference Links for Operational Insights and Operating Experience (OE)
Here are some Safety Considerations related to Residential Occupancies (non-inclusive) for Operations at Basement Fires that will support fireground operational safety:
- Conduct a thorough fire size-up and communicate the findings to all personnel on-scene before entering the building.
- Conduct an assessment of the Building Profile ( building construction type, structural assembly systems and features and age) and assesss fire behavior and intensity levels.
- Ensure an adequte Risk Assessement is conducted and that Risk versus Gain is determined
- Maintain situational awareness throughout the tactical deployment of crews within the interior of the structure
- Conduct a 360 degree perimeter assesement when feasible to determine access and egress points, fire location and travel and other mission critical operational perameters.
- Incident commanders and company officers should be trained and experienced in structure fire size up to avoid putting fire fighters at unneeded risk of working above fire-damaged floors.
- Do not enter a structure, room, or area when fire is suspected to be directly beneath the floor or area where fire fighters would be operating, or if the location of the fire is unknown.
- Never assume structural safety of any floor (regardless of the construction) having a significant fire under it.
- Conduct pre-incident planning inspections during the construction phase to identify the type of floor construction.
- If pre-planning is not conducted, assume residential construction and small commercial buildings built since the early 1990s may contain engineered wood I-joists.
- Report construction deficiencies noted during preplanning to local building code officials. For example, engineered wood floor joists should only be modified per manufacturer specifications—usually limited to cutting to length and removing pre–cut knockouts for utility access. Report damaged or cut chords or webs to building officials.
- Develop, enforce, and follow standard operating procedures (SOPs) on how to size up and combat fires safely in buildings of all construction types. Rapid intervention teams (RIT) should include a portable ladder with their RIT equipment when deployed at basement fires.
- Ensure Time Compression is considered: Ensure Command has the ability to monitor progress or elapsed incident time and adjusts strategic and tactical plans accordingly and in a time effective manner.
- Provide training on identifying signs of weakened floor systems (soft or spongy feel, heat transmitted through floor, downward bowing, etc.).
- Make fire fighters aware that all floor types can fail with little or no warning.
- Use a thermal imaging camera to help locate fires burning below or within floor systems, but recognize that the camera cannot be relied upon to assess the strength or safety of the floor. (Refer to the recent UL Test Data and Operational Safety Considerations ”Structural Stability of Engineered Lumber in Fire Conditions” available at http://www.uluniversity.us/ )
- Fire fighters should be trained on the use of thermal imaging cameras, including limitations and difficulties in detecting fire burning below floor systems. (See reference to UL above)
- Immediately evacuate and, if possible, use alternate exit routes when floor systems directly beneath the floor where fire fighters would be operating are weakened by fire.
- Use defensive overhaul procedures after fire extinguishment in structures containing fire-damaged floor systems of all types.
- Consider becoming active in the building code process and influence requirements for fire resistance of floor and ceiling systems to further fire fighter safety and health.
- Ensure RIT personnel area staged and have complete a site assessment of the building and occupany upon thier arrival and set-up
- Ensure that a rapid intervention team (RIT) is on the scene as part of the first alarm and in position to provide immediate assistance prior to crews entering a hazardous environment
Buffalo (NY) Fire Deparment- August 24, 2009 1815 Genesee Street, Buffalo, NY
Career Lieutenant Dies Following Floor Collapse into Basement Fire and a Career Fire Fighter Dies Attempting to Rescue the Career Lieutenant – New York (REPORT HERE)
The Structure, (pre-fire conditions)
On August 24, 2009, a 45-year-old male career lieutenant (Victim #1) died following a partial floor collapse into a basement fire, and a 34-year-old male career fire fighter (Victim #2) was fatally injured while attempting to rescue Victim #1. The career fire department was dispatched for “an alarm of fire” with reported civilian(s) entrapment. Arriving units discovered a heavily secured mixed commercial/residential structure with smoke showing. Following failed initial attempts to locate an entry to the basement, crews located a door on Side 2 that provided access down a flight of stairs to a basement entry door. Repeated attempts were made to force open this basement door in order to search for trapped civilians, but crews had difficulty gaining access through this door because it was made of steel and locked and dead-bolted on both sides. Other crews on scene performed primary searches of the 1st and 2nd floors with no civilians found.
Approximately 30 minutes into the basement fire, command ordered all interior crews to exit the structure to regroup because crews were still unable to gain access into the basement from Side 2. Additional manpower was sent with special tools to assist in breaching the basement door on Side 2. Victim #1 and two fire fighters from his crew entered into the structure from Side 1 to verify all fire fighters had exited a 1st floor deli. Victim #1, following a hoseline into the structure, was well ahead of the other two fire fighters when the 1st floor partially collapsed beneath him. Victim #1 fell with the floor into the basement, exposing him to the basement fire. The other two fire fighters immediately exited the deli after fire conditions quickly changed and shelving and displays fell on them; they were unaware of what had just occurred. Victim #1 made several Mayday calls from within the structure and activated his PASS device. Confusion erupted exteriorly on scene when trying to verify who was calling the Mayday, their exact location, and how they got into the basement. The incident commander was aware that he had crews attempting to gain access into the basement from Side 2 but was unaware that there had been a floor collapse within the deli section of the structure.
Simultaneously, Victim #2, a member of the fire fighter assistance and search team (FAST), was standing by outside Victim #1’s point of entry when the Mayday calls came out. It is believed that Victim #2 knew where Victim #1 was since he had gone in the structure with him earlier in the incident. Victim #2 grabbed a tool, went on air, and rushed into the structure. The FAST and additional personnel on scene concentrated on Side 2 initially while other fire fighters followed an unmanned hoseline into the deli. Crews within the deli quickly discovered a floor collapse and reported hearing a PASS device alarming. Victim #1 was immediately identified as missing during the first accountability check, but Victim #2 was not accounted for as missing until the third accountability check, more than 50 minutes after Victim #1’s Mayday. After the fire was controlled, both victims were discovered side-by-side in the basement where the 1st floor had partially collapsed. They were found without their facepieces on and with SCBA bottles empty. Victim #1’s PASS device was still alarming. They were pronounced dead on scene. Four fire fighters and one lieutenant suffered minor injuries during the incident. No civilians were discovered within the structure.
||Aug 24, 2009
||Career lieutenant dies following floor collapse into basement fire and a career fire fighter dies attempting to rescue the career lieutenant – New York
Key contributing factors identified in this investigation include working above an uncontrolled, free-burning basement fire; interior condition reports not communicated to command; inadequate risk-versus-gain assessments; and, crew integrity not maintained.
NIOSH has concluded that, to minimize the risk of similar occurrences, fire departments should:
- Ensure that all personnel are aware of the dangers of working above a fire, especially a basement fire, and develop, implement, and enforce a standard operating procedure (SOP) that addresses strategies and tactics for this type of fire.
- Ensure that the incident commander (IC) receives interior status reports and performs/continues evaluating risk-versus-gain.
- Ensure that crew integrity is maintained at all times on the fireground.
- Ensure that the incident commander (IC) receives accurate personnel accountability reports (PAR) so that he can account for all personnel operating at an incident.
- Ensure that a separate incident safety officer, independent from the incident commander, is appointed at each structure fire.
- Ensure that fire fighters use their self-contained breathing apparatus (SCBA) and are trained in SCBA emergency procedures.
Additionally, manufacturers, equipment designers, and researchers should:
- Conduct research into refining existing and developing new technologies to track the movement of fire fighters inside structures.
- Continue to develop and refine durable, easy-to-use radio systems to enhance verbal and radio communication in conjunction with properly worn self-contained breathing apparatus (SCBA)
Fire and Rescue Operations
(Photo courtesy of fire department. From NIOSH REPORT)
Recommendation #1: Fire departments should ensure that all personnel are aware of the dangers of working above a fire, especially a basement fire, and develop, implement, and enforce a standard operating procedure (SOP) that addresses strategies and tactics for this type of fire.
Discussion: Basement fires can be taxing and test a fire fighter’s knowledge and skill on how to combat it safely and effectively. Fire burning underneath floors can significantly degrade the floor system with little indication to fire fighters working above.1 They need to be aware of rapid heat buildup, little or no ventilation, limited accessibility, and whether it is a storage place for unknown hazards (e.g., combustibles, hazardous materials, and flammable liquids). Also of concern for fire departments is how to determine how long a fire has gone undetected. Fire fighters should be aware of what is stored on the floor directly above a basement fire, what the finished floor is comprised of (e.g., terrazzo, plywood, tongue-and-groove, tile, etc.), and what the floor structural members are comprised of (e.g., engineered wood floor joists, concrete, or steel). Structural support members may be directly exposed to fire, causing them to weaken and increase the likelihood of an above-floor collapse. Interior crew(s) intending to operate on the floor above a basement fire should limit their operating time, especially if ventilation, suppression, and accessibility are not progressing. The floor’s structural members will continue to weaken as fire and heat intensify. Specifying an exact length of time for how long suppression crew(s) should operate above a basement fire is questionable, and the IC should make that determination by performing a hazard analysis/risk assessment. The fire department did not have an SOP specifically addressing strategies and tactics when combating basement fires. SOPs should be developed to address structural fire fighting operations specific to basement fires, because these types of fires present a complex set of circumstances and following established SOPs will minimize the risk of serious injury to fire fighters.
During this incident, fire fighters were unable to access the basement, unable to ventilate the basement fire, and unaware of the fire load found within the basement. Initially, the department did not cut a hole in the 1st floor apartment or deli and use their Bresnan distributor, in fear of injuring reported trapped civilians. Note: The Bresnan distributor is a type of cellar nozzle used to suppress fire through steam conversion. The use of a cellar nozzle, like a Bresnan distributor, during the initial stages of the basement fire may have assisted in containing the fire and/or allowing better operating conditions for fire fighters to access the basement.2 Attempts were made to flow water on the 1st floor where fire had vented through, but this effort was not successful. Fire fighters should also recognize that fire venting through a floor is a late indication of a weakened floor system.
Recommendation #2: Fire departments should ensure that the incident commander (IC) receives interior status reports and performs/continues evaluating risk-versus-gain.
Discussion: Among the most important duties of the first officer on the scene is conducting an initial size-up of the incident. A proper size-up begins from the moment the alarm is received, and it continues until the fire is under control. The size-up should also include assessments of risk-versus-gain during incident operations, especially after primary searches have been conducted.2-7 The size-up should include an evaluation of factors such as the fire size and location, length of time the fire has been burning, conditions on arrival, occupancy, fuel load and presence of combustible or hazardous materials, exposures, time of day, and weather conditions. Information on the structure itself should include size, construction type, age, condition (e.g., evidence of deterioration, weathering), evidence of renovations, lightweight construction, loads on roof and walls (e.g., air conditioning units, ventilation ductwork, utility entrances), and available preplan information are all key information that can affect whether an offensive or defensive strategy is employed. The incident commander should be willing to change his strategy and plan based on continued size-ups and risk assessments until the fire is brought under control. Conducting accurate size-ups and receiving interior/exterior status updates is critical to the safety of fire fighters on the incident, rescue/recovery efforts, and overall control of the incident. “The decision to commit interior firefighting personnel should be made on a case-by-case basis with proper risk-benefit decisions being made by the incident commander. The commitment of firefighters’ lives for saving property and an unknown or marginal risk of civilian life must be balanced appropriately.” 8 The fireground is very dynamic, and conditions can either improve or deteriorate based on fire suppression activities, and available resources, and most importantly assessments/size-ups of the incident are necessary to detect a change on the fireground.
During this incident, the fire department was attempting to gain access to reported trapped civilian(s) in a basement. The command post was established at the front of the structure providing views of Side 1 and Side 2. The basement contained heavy smoke and fire and was inaccessible from exterior and interior access doors. The initial IC and the IC who assumed command performed initial size-ups and received radio updates on fire and smoke conditions from personnel working on the incident, but not all interior findings were reported. Crews working in the 1st floor apartment encountered fire venting through the floor on Side 4 as early as 9 minutes after the first apparatus arrived on scene. Ten minutes later, Victim #1 was flowing water on fire that had vented in the corner of Side 3 and Side 4 of the deli. This was the same general area where crews within the 1st floor were working. The only thing separating the apartment and deli was a wall of floor coolers. The basement fire burned uncontrolled for more than 30 minutes while fire fighters continued attempts to gain access to the basement. Incident updates on the radio included transmissions such as “untenable” and “time to get out,” prior to the 1st floor partial collapse. The IC also mistook “water on the fire” as fire fighters actually attacking the basement fire from Side 2. This provided the IC with a false sense of progress on combating the basement fire. Also, during this incident, the IC was at times monitoring multiple radio channels and some additional transmissions may not have been received. Radio transmissions are very important for the IC to hear, acknowledge, and prioritize so that the IC can maintain situational awareness, and accurately and effectively manage and direct fireground operations. A chief’s aid or incident command technician assigned to the IC may have assisted the IC in monitoring the fireground channels and distinguishing key radio traffic and updates. It is reasonable to believe that, as time progressed and basement fire conditions continued to be uncontrolled, that the chances of survival diminished for any potentially trapped civilians exposed to the heat or products of combustion found within the smoke. According to fire investigators with the fire department, only the bodies of Victim #1 and Victim #2 were found within the structure.
Recommendation #3: Fire departments should ensure that crew integrity is maintained at all times on the fireground.
Discussion: Fire fighters should always work and remain in teams whenever they are operating in a hazardous environment.2 Team integrity depends on team members knowing who is on their team and who is the team leader; staying within visual contact at all times (if visibility is low, teams must stay within touch or voice distance of each other); communicating needs and observations to the team leader; and rotating together for team rehab, team staging, and watching out for each other (e.g., practicing a strong buddy system). Following these basic rules helps prevent serious injury or even death by providing personnel with the added safety net of fellow team members. Teams that enter a hazardous environment together should leave together to ensure that team continuity is maintained. 3
During this incident, raw video captured the FAST working on Side 1 of the structure (same side that Victim #1 had entered) during Victim #1’s “Mayday.” At the same time, Victim #2, assigned to the FAST, was seen pointing at Side 1, donning his SCBA, and entering the structure as other fire fighters were exiting from Side 1. The FAST was activated and ordered to Side 2 where it was believed the “Mayday” transmission came from. Victim #2 went missing following the “Mayday” and his whereabouts were unknown until the recovery of Victim #1. Also, Victim #1 entered the deli not realizing that two of his team members from R1 were not following behind. Not verifying your crew is with you and/or working alone increases the risk to individuals and possibly to others during search and rescue efforts. During interviews, the fire department commented on an increase in “freelancing” following the Mayday.
|Photo 6. Interior view of deli following partial floor
collapse and recovery operations.
(Photo courtesy of police photographer. From NIOSH REPORT)
|Photo 7 . Views of materials stored within basement.
(Photos courtesy of police photographer. From NIOSH REPORT)
Recommendation #4: Fire departments should ensure that the incident commander (IC) receives accurate personnel accountability reports (PAR) so that he can account for all personnel operating at an incident.
Discussion: An important aspect of an accountability system is the personnel accountability report (PAR). A PAR is an organized on-scene roll call in which each supervisor reports the status of his crew when requested by the IC or emergency dispatcher.2 The use of an accountability system is recommended by NFPA 1500 Standard on Fire Department Occupational Safety and Health Program9 and NFPA 1561 Standard on Emergency Services Incident Management System.10 A functional personnel accountability system requires the following:
- development of a departmental SOP
- training all personnel
- strict enforcement during emergency incidents
As the incident escalates, additional staffing and resources may be needed, adding to the burden of tracking personnel. An incident command board should be established at this point with an assigned accountability officer or aide. As a fire escalates and additional fire companies respond, a chief’s aide or accountability officer assists the incident commander with accounting for all fire fighting companies at the fire, at the staging area, and at the rehabilitation area. With an accountability system in place, the incident commander may readily identify the location and time of all fire fighters on the fireground. A properly initiated and enforced accountability system that is consistently integrated into fireground command and control enhances fire fighter safety and survival by helping to ensure a more timely and successful identification and rescue of a disoriented or downed fire fighter. This department has developed and implemented SOPs governing accountability and even assigns an accountability officer to the IC to assist with radio transmissions and PARs.
An accountability officer was assigned to assist the IC during the incident. A PAR was immediately obtained following the rescue attempts for Victim #1. Victim #1 was identified as “missing,” but Victim #2 was incorrectly identified as “accounted for.” Victim #2 was incorrectly “accounted for” during a second separate PAR. Prior to a third PAR, 50 minutes following the floor collapse, Victim #2 could not be visibly accounted for on the fireground and his whereabouts were unknown. Officers need to visually account for their members prior to providing an “all accounted for” to the IC or accountability officer. Quickly being able to account for all personnel at an incident is paramount and can determine how an IC orders search and rescue efforts or other suppression activities.
Recommendation #5: Fire departments should ensure that a separate incident safety officer, independent from the incident commander, is appointed at each structure fire.
Discussion: According to NFPA 1561 Standard on Emergency Services Incident Management System, 11 “The incident commander shall have overall authority for management of the incident and the incident commander shall ensure that adequate safety measures are in place.” This shall include overall responsibility for the safety and health of all personnel and for other persons operating within the incident management system. While the incident commander is in overall command at the scene, certain functions must be delegated to ensure adequate scene management is accomplished. 10 According to NFPA 1500 Standard on Fire Department Occupational Safety and Health Program, 9 “as incidents escalate in size and complexity, the incident commander shall divide the incident into tactical-level management units and assign an incident safety officer (ISO) to assess the incident scene for hazards or potential hazards.” These standards indicate that the incident commander is in overall command at the scene but acknowledge that oversight of all operations is difficult. On-scene fire fighter health and safety is best preserved by delegating the function of safety and health oversight to the ISO. Additionally, the incident commander relies upon fire fighters and the ISO to relay feedback on fireground conditions in order to make timely, informed decisions regarding risk versus gain and offensive-versus-defensive operations. The safety of all personnel on the fireground is directly impacted by clear, concise, and timely communications among mutual aid fire departments, sector command, the ISO, and the incident commander. NFPA 1521 Standard for Fire Department Safety Officer defines the role of the ISO at an incident scene and identifies duties such as recon of the fireground and reporting pertinent information back to the incident commander; ensuring the department’s accountability system is in place and operational; monitoring radio transmissions and identifying barriers to effective communications; and ensuring established safety zones, collapse zones, hot zones, and other designated hazard areas are communicated to all members on scene.11 Larger fire departments may assign one or more full-time staff officers as safety officers who respond to working fires. In smaller departments, every officer should be prepared to function as the ISO when assigned by the incident commander. The presence of a safety officer does not diminish the responsibility of individual fire fighters and fire officers for their own safety and the safety of others. The ISO adds a higher level of attention and expertise to help the fire fighters and fire officers. The ISO must have particular expertise in analyzing safety hazards and must know the particular uses and limitations of protective equipment. 4
During this incident, the designated department ISO was not dispatched until the incident was upgraded to a 2nd alarm because it occurred after the normal duty shift of the ISO. The ISO did not arrive until rescue/recovery operations had begun on breaching the Side 4 wall. The presence of an ISO throughout this incident would have allowed the IC to focus on supervising the incident while the ISO directed safety operations.
Recommendation #6: Fire departments should ensure that fire fighters use their self-contained breathing apparatus (SCBA) and are trained in SCBA emergency procedures.
Discussion: Fire fighters are tasked at times to operate within environments which pose inhalation hazards (e.g., toxic smoke and oxygen deficiency12), defined by OSHA as immediately dangerous to life and health (IDLH). Proper training along with an implemented and enforced policy or procedure will assist fire fighters with proper maintenance, use, and removal of a SCBA. OSHA 29 CFR 1910.134 (g)(4)(iii) states, “all employees engaged in interior structural firefighting use SCBAs.”13 During this incident, the medical examiner stated both victims died from inhalation of products of combustion. The medical examiner also indicated that the victims’ COHb levels (a measure of carbon monoxide in the bloodstream) were over 50%. Even if nothing but carbon dioxide, water vapor, and nitrogen were present in the fire products and these were to mix with the air being breathed by a fire fighter, then the oxygen percentage would be reduced below the normal 21%. At 15% oxygen, fire fighters can experience lethargy, poor coordination, and confused thinking. The two principal toxins in smoke—carbon monoxide and hydrogen cyanide—act to deprive the brain of oxygen, and their effects would be enhanced due to the lower levels of oxygen in the air.14 Both victims were discovered without their facepieces on.
Due to the smoke conditions, both victims would have had to have been on air when entering the structure. It has not been determined why both victims were found without their facepieces on, but NIOSH investigators have theorized the following possibilities:
- Victim #1 removed his facepiece to transmit his “Mayday.”
- Both victims’ facepieces were unintentionally knocked off when falling into the basement.
- The facepieces were removed because they ran out-of-air or other emergency situation.
Emergencies created by, or associated with, SCBAs can be overcome in several ways. Fire departments can develop and implement a comprehensive respiratory protection program15 that includes fire fighter fitness, training, competency, and skill in SCBA and emergency procedures. Firefighters should remember the first rule in any emergency situation, and that is not to panic. Panic causes increased breathing air consumption and inability to focus on emergency procedures. If fire fighters become lost, trapped, or disoriented they need to focus on managing remaining air in their SCBA cylinder until other fire fighters can make a rescue attempt. Removing one’s facepiece in an IDLH atmosphere can immediately expose the respiratory system to a potentially fatal environment, thus incapacitating an individual. Choosing to leave one’s SCBA facepiece on may be the best chance in providing additional time for a fire fighter to be rescued. Fire fighters should follow their department’s SOPs regarding emergency SCBA procedures and emergency communications.
Recommendation #7: Manufacturers, equipment designers, and researchers should conduct research into refining existing and developing new technologies to track the movement of fire fighters inside structures.
Discussion: Fire fighter fatalities often are the result of fire fighters becoming lost or disoriented on the fireground. The use of systems for locating lost or disoriented fire fighters could be instrumental in reducing the number of fire fighter deaths on the fireground. The National Institute of Standards and Technology (NIST) has been evaluating the feasibility of real-time fire fighter tracking and locator systems for some time.16, 17 Another group researching advanced fire fighter locator and tracking systems is the Maryland Fire Rescue Institute, located at the University of Maryland – College Park.18 Research into refining existing systems and developing new technologies for tracking the movement of fire fighters on the fireground should continue. While it is not clear that the use of this technology in this incident would have prevented the fatalities, such technology could potentially have reduced the search time by aiding rescue teams in pin-pointing the location of the missing fire fighters. This new technology must function properly in the severe fire conditions often encountered during rescue operations.
During the initial stages of the incident, it was not known who was transmitting the Mayday, where exactly they were in the basement, or how they got into the basement. Victim #2 went accounted for approximately 50 minutes before a determination was made that Victim #2 was also missing. It was not until rescue/recovery crews visually located the victims that they accounted for the location of Victim #2. This technology may have assisted the fire department during this incident in more quickly locating Victim #1 and Victim #2.
Of importance, Victim #1’s PASS device was alarming during the Mayday and when he was discovered, but it was reported to NIOSH investigators that Victim #2’s PASS device was never heard. Victim #2’s PASS device was evaluated as part of NIOSH’S NPPTL SCBA inspection. Victim #2’s PASS device failed to function when tested, but after the batteries were replaced within the PASS device, it alarmed appropriately. It has not been determined if the battery life was exhausted prior to Victim #2 going into the structure. It is important to note that the 2007 revision to NFPA 1982 Standard on Personal Alert Safety Systems (PASS) includes new heat and flame resistance requirements resulting from documented reports where PASS devices were not heard during fatal fireground incidents. 19 Laboratory testing conducted by NIST determined that exposure to high temperature environments caused the loudness of the tested PASS alarm signal to be reduced. This reduction in loudness can cause the alarm signal to become indistinguishable from background noise at an emergency scene. Initial laboratory testing by NIST highlighted that this sound reduction may begin to occur at temperatures as low as 300°F. Thus the use of PASS devices meeting NFPA 1982, 2007 Edition requirements is highly recommended.
Recommendation #8: Manufacturers, equipment designers, and researchers should continue to develop and refine durable, easy-to-use radio systems to enhance verbal and radio communication in conjunction with properly worn self-contained breathing apparatus (SCBA).
Discussion: The use of Personal Protective Equipment (PPE) and an SCBA make it difficult to communicate, with or without a radio.20-22 Faced with the difficult task of communicating while wearing a SCBA, fire fighters sometimes momentarily remove their facepieces to transmit a message directly or over a portable radio. Considering the toxic and oxygen-deficient hazards posed by a fire and the resulting products of combustion, removing the SCBA facepiece, even briefly, is a dangerous practice that should be prohibited. Even small exposures to carbon monoxide and other toxic agents present during a fire can affect judgment and decision-making abilities. To facilitate communication, equipment manufacturers have designed facepiece-integrated microphones, intercom systems, throat mikes, and bone conduction mikes worn in the ear or on the forehead.20-22
During this incident, interviewed fire fighters complained of radio transmissions being unintelligible at times or not heard at all. Although NIOSH investigators are not certain why Victim #1 and Victim #2 were found without their facepieces on, one theory is that Victim #1 may have momentarily removed his facepiece to better transmit his Mayday. Fire fighters recall hearing his transmissions as they came across the radio and also emanating clearly from the structure.
Recent testing by the National Institute for Standards and Technology (NIST) of portable radios in simulated fire fighting environments has identified that radios are vulnerable to exposures to elevated temperatures. Some degradation of radio performance was measured at elevated temperatures ranging from 100°C to 260°C, with the radios returning to normal function after cooling down. Additional research is needed in this area.16, 20 Fire service radios also need to be waterproof as normal fireground conditions dictate that radios are frequently exposed to excessive amounts of water during routine use through exposure to hose streams, overspray, water dripping from overhead, etc.
FDNY- August 27, 2006 Walton and East Mount Eden Avenues, Bronx, NY
Floor Collapse at Commercial Structure Fire Claims the Lives of One Career Lieutenant and One Career Fire Fighter – New York (REPORT HERE)
On August 27, 2006, a 43-year-old male career Lieutenant (victim #1) and a 25-year-old male fire fighter (victim #2) died after the floor they were operating on collapsed at a commercial structure fire. At approximately 1230 hours, crews were dispatched to a fire. The victims’ engine was dispatched at 1236 hours as an additional unit alarm and arrived on the scene at approximately 1240 hours. At approximately 1251 hours, victim #1, victim #2 and fire fighter #1 advanced a 2 ½-inch hand line through the front of the structure and down an aisle toward the rear of the store. The fire was located in the rear interior of the structure (discount store) that sold a variety of numerous small household commodity items. Approximately three minutes later, the structural members supporting the floor directly below the victims failed. The V-shaped collapse of the floor caused victim #1 and victim #2 to fall into the basement and shelving stocked with merchandise to fall in on top of them. Multiple MAYDAYs were transmitted and the fire fighter assist and search team (FAST) was deployed to the front of the structure where they assisted in the rescue of numerous members who had been operating in the interior of the structure at the time of the collapse. Battalion Chief #1, Lieutenant #1 and fire fighter #1 were freed from the debris. At approximately 1415 hours, victim #1 was removed from the debris in the basement and transported to the hospital. He died the next day as a result of his injuries. At approximately 1435 hours, victim #2 was removed from the basement and transported to the hospital where he was pronounced deceased as a result of his injuries.
||Aug 27, 2006
||Floor collapse at commercial structure fire claims the lives of one career lieutenant and one career fire fighter – New York
NIOSH investigators concluded that, to minimize the risk of similar occurrences, fire departments should:
- consider the possibility of a substandard structure when building information is not available from pre-incident plans
- consider the live load of water on the structure and go defensive when water load potentially compromises the structural integrity
Additionally, municipalities should:
- explore means of coordinating information sharing between building and fire departments to increase safety for fire fighters and civilians
- consider conducting inspections on all commercial structures where a change of occupancy has occurred or renovations are known or suspected, giving special attention to non-sprinklered commercial retail structures
Recommendation #1: Fire departments should consider the possibility of a substandard structure when building information is not available from pre-incident plans, and implement a defensive strategy when no occupants are at risk.
Discussion: The threat of a collapse of some type (i.e. roof, ceiling, floor or wall) is a possibility in any structural fire due to the effects of fire, water application, age, insects, and alterations. It is a high probability that a fire department is unaware of structural defects caused by age, insects and alterations. To minimize the risk of injury or death to fire fighters during structural operations, the size-up and risk assessment includes many factors, which include: age of the building (deterioration of structural members, evidence of weathering, use of lightweight materials in new construction), occupancy, and renovations or modifications to the building.3,4,5
Pre-incident plans are an effective tool in preventing injuries and deaths of fire fighters due to structural collapse. They allow fire departments to determine factors, such as, age of the structure, structural integrity, type of materials used in the structure, and amount of load on the roof that could weaken the supports, etc. However, in numerous cities and towns where buildings number in the hundreds of thousands, fire departments lack the manpower to pre-plan all buildings under their protection. Often fire departments are limited to targeting buildings that have a unique construction or pose a known hazard.
In floor collapses that have occurred, such as those at a New York City drug store (October 17, 1966) and at a Boston hotel (June 17, 1972), there were no warning signs, and no time to act and withdraw fire fighters to safety. At both of these floor collapses, unauthorized alterations on the structure contributed to the structural failure.5
“The potential for structural collapse is one of the most difficult factors to predict during initial size-up and ongoing fire fighting. Structural collapse usually occurs without warning.” 3 When pre-incident plan information on the fire structure is not available, occupants have been evacuated, and evidence of structural deterioration and/or modification cannot be determined, a defensive strategy should be implemented. A defensive strategy would help ensure fire fighter safety and is warranted in structures that lack pre-incident plans, no occupants are at risk, and where the potential for numerous unrecognized hazards exists, such as substandard construction and building deterioration.
Fire departments operating in older businesses and homes should be suspicious of potential alterations and renovations which could result in unsupported loads and unusual voids. These alterations may be hidden by sheetrock (drywall) or flooring and built up flooring which is difficult to detect during inspections and virtually impossible to detect during firefighting operations. The older the structure, the greater the possibility of renovation or remodel.
In this case, there were no current pre-incident plans for the structure; the occupants had evacuated upon the fire department’s arrival, and compromised structural integrity was not immediately evident. Structural alterations had been made to the girders, columns, and floor in order to presumably level and support the floor. A post incident inspection showed 2 x 4 boards being used inappropriately (in orientation and stability) as a floor joist. A cluster of nails were used in lieu of bolts to attach gusset plates to the columns and girders. Sheets of plywood were added to the floor with no structural support around the sheet’s edges nor at 12”, 16” or even 24” intervals in accordance with standard building codes. Subflooring (i.e., plywood, wafer board, etc.) needs to be fastened around the sheet’s edges and at interval spacing (generally every 16 inches, but spacing may vary according to load requirements) to support floor joists. The interior support members of the structure suffered from severe rot at the base of the timber columns.
Recommendation #2 : Fire departments should consider the live load of water on the structure and go defensive when water load potentially compromises the structural integrity.
Discussion: A forensic engineering analysis of the fire building demonstrated that the weight of water added to the building from the fire fighting operations was approximately 50% of the rated structural capacity of the floor.2 As noted previously, however, timbers that supported the ground floor had rotted. Thus, the actual structural capacity of the floor was less than rated. Although the ultimate cause of the collapse was the rotted timbers, the weight of the water applied during the fire fighting operations, in addition to the weight of fire fighters, store merchandise, etc., likely contributed to the collapse. Given the many unknowns during fire fighting operations, including in most incidents the rated capacity of floors, incident commanders need to continuously consider the impact of water weight on structural integrity, and shift to defensive strategies when structural integrity is potentially compromised.
Firefighting operations can drastically increase the live load on the fire building. This can be due to the weight of:
- the firefighters with their protective equipment and tools,
- the hose-line brought into the fire building, and
- the water used to attack the fire6.
A 2 ½ -inch hose-line can deliver approximately 250 gallons of water per minute. 5 This adds about 2,082 pounds per minute into the fire building. If multiple hose-lines are operating, the weight of the water can be tremendous.
When operating in an offensive mode, a buildup of water within a building requires that immediate action be taken to alleviate these conditions. 6 The remedy may be as simple as controlling the excess flow from the hose-line or moving fire debris that is restricting runoff. When using large amounts of water, it is always advisable to provide for drainage when necessary. This can be accomplished any number of ways from chutes with traps to actual holes drilled to provide relief. 6
It must be recognized that at the same time that this additional weight is being introduced into the fire building, the fire and water are weakening the structure. Under these conditions, a defensive strategy is best when no civilians are in the structure. 5
In this case, civilians had evacuated the fire building upon the fire department’s arrival. The structures’ configuration only enabled an initial attack through the front of the structure and down narrow aisle ways to the rear of the structure where the origin of the fire was located. Prior to the collapse, three 2 ½-inch hose-lines (operating 17 minutes, 8 minutes, and 2 minutes, respectively) were flowing water through and into the rear of the structure. The added weight and flow of the water could have contributed to the floor collapse because of the rotted support columns decreasing the timber frame system’s ability to equalize the water load across the floor.
|Diagram 2. Shows location of victims on the structure’s floor above the girder that failed. From the NIOSH REPORT
Recommendation #3 : Municipalities should explore means of coordinating information sharing between building and fire departments to increase safety for fire fighters and civilians
Discussion: Information on building construction, renovations, and alterations can help Incident Commanders develop strategies and tactics that effectively fight fires while attending to fire fighter safety. Pre-incident plans are a useful tool for ensuring that fire departments and Incident Commanders have information on building construction and contents to guide decision-making on the fireground. In urban areas with large numbers of existing structures, it may not be feasible to develop pre-incident plans for all or most structures, and for fire departments to regularly revisit structures to update pre-incident plans. Municipal building departments that issue building permits and conduct code inspections may collect, or be in position to collect, information that may be useful to fire departments. Municipalities should consider exploring mechanisms by which building information relevant to fire fighter and civilian safety can be collected and shared between building and fire departments. As one example, building departments could notify fire departments when building permits are issued. This would result in fire departments being aware of these building alterations, and to possibly target these buildings for a pre-incident plan. Priority should be given to sharing such information for targeted hazards identified by fire departments.
Recommendation #4: Municipalities should consider conducting inspections on all commercial structures where a change of occupancy has occurred or renovations are known or suspected, giving special attention to non-sprinklered commercial retail structures
Discussion: Occupancy changes understandably occur with great frequency. However, every effort should be made as new permits are issued to aggressively inspect any occupancy change. It is critical that municipalities assess that any renovations or remodeling meets current codes, and that original and renovated supports are capable of supporting the new occupancies. These building inspections should specifically consider the loading or redistribution of stock to ensure that flooring can handle dead and live loads.