WORKPLACE SOLUTIONS

From the National Institute for Occupational Safety and Health

DEPARTMENT OF HEALTH AND HUMAN SERVICES

Centers for Disease Control and Prevention

National Institute for Occupational Safety and Health

Summary

Fire fighters are at significant risk 

for injury or death due to structural collapse during fire-fighting 

operations. Structural collapse 

often occurs without warning. 

The National Institute for Occupational Safety and Health 

(NIOSH) recommends that the 

Incident Commander establish 

defensive operations and collapse zones when there is potential for a structural collapse during fire-fighting operations.

Preventing Deaths and Injuries to 

Fire Fighters by Establishing Collapse 

Zones at Structure Fires

Description of

Exposure

The United States Fire Administration reported that 1,230 fire fighters 

died between 2000 and 2012. Structural collapse caused 142 of these 

fire fighter deaths (11.5%). Structural collapse often results in multiple fire fighter injuries and fatalities. 

The number of fatalities includes fire 

fighters killed by collapse inside and 

outside a structure. 

Although structural collapse is a significant cause of injury and death to 

fire fighters, the potential for a structural collapse is one of the most difficult situations to predict. A collapse 

zone is defined as the area around the 

perimeter of a structure that could 

contain debris if the building collapsed. This area is often defined by 

establishing a perimeter at a distance 

from the building that is equal to 11⁄2 

times the height of the structure. 

When established, a collapse zone 

should be identified by a fireground 

transmission, colored tape, signage 

cones, flashing beacons, fences, or 

other appropriate means. A “No Entry” policy should be enforced by the 

Incident Commander, Incident Safety Officer, Division/Group Supervisors, and company officers. When it 

is not possible or practical to visually mark a collapse zone, the Incident 

Commander should verbally identify 

the collapse zone area to all fireground 

personnel via radio or other communication methods. During structure fires, the Incident Commander 

should initially evaluate and continually reevaluate risk factors, including 

the potential for structural collapse 

based on direct observations, reports, 

and pre-incident plan information. 

An exclusion zone should be established during large or extended firefighting operations. An exclusion zone 

is defined as a zone established by the 

Incident Commander to prohibit specific activities in a specific geographic 

area. If the fire is not contained and an 

exterior (defensive) attack becomes 

necessary, the exclusion zone is moved 

far enough away from the structure to 

place the fire fighters outside of the 

collapse zone. In large or extended 

fire-fighting operations, these zones 

must be continually adjusted as necessary, and all personnel at the scene 

must be made aware of the exclusion 

zone or collapse zone locations. 

Determining when to establish a collapse zone starts with a community 

risk assessment program. Community risk assessments satisfy many fire 

department objectives, but one of the 

most important aspects is to evaluate 

the fire risk associated with occupancy and construction classifications. A 
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community risk assessment program, coupled with a preincident planning initiative that evaluates building construction, structural integrity, fire load, and fire protection 

systems is a vital tool for safely fighting fires. Fire departments should ensure all members are trained in the organization’s rules of engagement, risk assessment, and situational awareness procedures. 

Understanding the influence that building design, construction, and conditions have on structural collapse potential has a direct correlation to safe fireground operations and fire fighter survivability. A collapse zone should 

be established whenever the risk of structural collapse is 

identified as a potential occurrence. 

Fire departments should not rely solely on the amount of 

time a fire has been burning as a collapse predictor. External loads, such as a parapet wall, steeple, overhanging 

porch roof, awning, sign, or large electrical service connections may also cause structural collapse. Other factors to consider include: 

 Construction type

 Age and condition of the building

 Pre-existing structural damage/deterioration 

 Structural weakness caused by explosion or impact

 Presence of free-standing parapets

 Presence of wall anchor plates or stars 

 Engineered load systems/lightweight construction

 Types of doors and windows 

 Roof design and covering including HVAC units on 

fast food occupancy roofs

 Renovation/modifications to structure 

 Height of the building

 Fire duration, size and location

 Fuel loads

 Fire behavior

 Fire protection features such as sprinkler systems and 

fire walls

 Weight of fire fighters and water used for extinguishment

Free standing parapets are often identified as a special 

risk factor in ordinary (brick) construction buildings (See 

Diagram 1 and Photo 1). In many cases, roof collapse 

causes a parapet to become unstable or collapse without warning.

Diagram 1. An example of a parapet wall.

Photo 1. Building with parapet wall (Courtesy of 

Buildingsonfire.com)
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Case Studies

Case Study 1

On June 17, 2011, a 22-year-old male paid on-call fire 

fighter received fatal injuries when he was struck by 

bricks and falling debris during an exterior wall collapse 

at a commercial structure fire. Crews were operating in a 

defensive mode for about 45 minutes attempting to extinguish a fire in a 96-year-old brick and masonry structure. The building housed an antique store with living 

quarters located in a rear addition. At the time of the 

collapse, the victim and another fire fighter were moving 

a 35-foot aluminum ground ladder that had been placed 

during initial fire-fighting operations (See Photo 2). No 

other fire fighters were injured in the collapse. 

Contributing factors included fire fighters with limited 

experience entering a collapse zone to move a ground ladder, entering a collapse zone in close proximity to master 

stream operations, limited visibility at the side and the 

rear of structure possibly obscuring signs of pending collapse, and limited training on structure collapse hazards.

Case Study 2

On May 21, 2009, a 36-year-old male career fire fighter 

was seriously injured while operating on the outside of a 

structure when the front overhang of a bowstring truss 

roof system collapsed and struck him.

The department’s Deputy Chief arrived on the scene 

nine minutes after the initial crew had arrived and determined the fire should be fought defensively. However, this order was not relayed over the radio or confirmed 

with all crews and a collapse zone was not established. A 

crew was operating a 2 1⁄2-inch handline just outside the 

structure approximately 20 minutes after the first apparatus arrived when the overhang collapsed trapping the 

nozzleman (See Photo 3).

Members immediately rushed to rescue the trapped fire 

fighter. A Personnel Accountability Report (PAR) was 

completed and the trapped fire fighter was removed and 

transported to a local hospital.

Note: 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 communicated over the radio.

Contributing factors that led to the injury included inadequate incident management and risk analysis, a wellinvolved structure with hazardous structure features, and 

fire fighters operating in a potential collapse area or zone. 

In both cases, collapse occurred without warning, reinforcing the need to consider building construction, fire 

involvement, length of time the fire had been burning, 

and other factors when evaluating the risk of collapse.

Controls

NIOSH recommends the following precautions and actions to minimize hazards and risks to fire fighters due to 

structural collapse during fireground operations. 

Pre-Incident

 Every fire department should implement a community risk assessment program that includes occupancy type and construction classifications.

Photo 2. Defensive operations at structure fire just after 

the collapse on “Side D” in Case Study 1.

Photo 3. The front overhang that collapsed injuring a fire 

fighter as described in Case Study 2.
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 Every fire department should implement a preincident planning program that complies with NFPA 

1620, Standard for Pre-Incident Planning. This includes initial and periodic review, testing, updating 

data, and refining the process.

 States, municipalities, and authorities having jurisdiction should design and implement a placarding system to identify high risk collapse prone buildings to 

support a timely size-up and Incident Action Plan development for initial arriving companies. 

 All fire fighters and fire officers should be trained in 

building design and construction in relation to structural collapse potential.

 Fire departments should implement clear rules of engagement and initial scene size-up which include risk 

assessment and situational awareness.

Incident 

 An incident management system should be used 

from the beginning of each incident to the completion of all operations.

 The Incident Commander should appoint division/

group supervisors (tactical level management) to ensure the safety of members operating in an immediately dangerous to life or health (IDLH) environment. 

 The Incident Commander should appoint a Safety 

Officer to monitor conditions and operations to ensure the conditions and operations fall within the parameters of the department’s rules of engagement. 

 Assistant Safety Officer(s) should be appointed and 

assigned as needed.

 The Incident Commander should always assess the 

survivability profile for civilians and fire fighters when 

determining whether offensive or defensive operations should be conducted. 

 The initial size-up should consider the type and condition of the structure and location of the fire, and 

any indications of potential structural weakness or 

collapse. 

 In buildings of Type III Ordinary (unreinforced masonry or reinforced masonry) or Type IV Heavy Timber 

construction including Mill and Semi-Mill construction, the Incident Commander should be focused on 

the high probability of internal and external collapse, 

establish defensive operations, establish and control 

collapse zones in multiple divisions and possibly in

exposure properties, and expect collapse to occur.

 When conditions become unsafe or are judged to be 

unsafe, the Incident Commander should immediately direct the Dispatch Center to transmit an audible 

evacuation tone (emergency traffic tone) or alert to 

notify fire fighters to abandon the structure and conduct a Personnel Accountability Report (PAR). Also 

multiple air horn blasts should be used to warn fire 

fighters to abandon the structure.

 When a structure is abandoned during fireground operations, all members should withdraw to safe positions outside the building, the Incident Commander 

should perform a PAR, and a collapse zone should be 

established. The structure should not be re-entered 

without orders from the Incident Commander and 

a risk assessment performed by the Safety Officer.

 When a collapse zone is established, all fire-fighting 

operations should be conducted from positions outside the collapse zone using master streams (e.g. deck 

guns and ladder pipes) or large volume hose streams.

 All fire fighters should maintain situational awareness 

and conduct continuous risk assessments throughout 

the incident. Unsafe or changing conditions should be 

immediately reported to their company officer, Division/Group Supervisor, and the Incident Commander.

 Whenever possible, the collapse zone should be marked 

by visible barriers or warning devices. A standard system should be established to mark a collapse zone. (Red 

“HAZARD ZONE – DO NOT ENTER” barrier tape is 

recommended for this purpose.)

 The collapse zone perimeters must be continuously monitored to ensure that no one enters the collapse zone. Marking and/or monitoring of the hazard 

zone is particularly important for incidents when the 

transfer of “Command” occurs multiple times, incidents of long duration and in situations where the incident scene covers a large geographical area.

 After a fire is under control when a structural collapse has occurred or has the potential to occur, the 

structural stability of the building should be thoroughly evaluated prior to any further operations.

Post Incident

 Every fire department should conduct a post incident 

analysis for incidents involving a near-miss, injury, or 

fire fighter fatality.

 Every fire department should periodically update 

their community risk assessment program and preincident planning process based on recommendations 

from post incident analysis reports.
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Acknowledgments

The principal contributors to this publication were Murrey Loflin, Jay Tarley, and Virginia Lutz, National Institute for Occupational Safety and Health, Fire Fighter Fatality Investigation and Prevention Program.

References

CommandSafety.com [2010]. Predictability of occupancy performance during suppression operations [http://commandsafety.com/2010/02/predictability-of-occupancy-performance-during-suppression-operations]. 

CommandSafety.com [2009]. Building knowledge = firefighter 

safety, know your district and its risk [http://commandsafety.com/2009/06/fireems-safety-health-and-survival-weekday-two-building-knowledge-firefighter-safety-know-yourdistrict-and-its-risk/]. 

NFPA [2007]. NFPA 1500: standard on fire department occupational safety and health program. Quincy, MA: National 

Fire Protection Association.

NIOSH [2010]. Career fire fighter seriously injured from collapse of bowstring truss roof – California. Fatality Assessment 

and Control Evaluation (FACE) Report F2009-21. http://

www.cdc.gov/niosh/fire/reports/face200921.html 

NFPA [2010]. NFPA1620: standard for pre-incident planning. 

Quincy, MA: National Fire Protection Association. 

NIOSH [2012]. Paid-on-call fire fighter killed by exterior wall 

collapse during defensive operations at a commercial structure fire—Illinois. Fatality Assessment and Control Evaluation (FACE) Report F2011-15. http://www.cdc.gov/niosh/

fire/reports/face201115.html 

NIOSH [1999]. NIOSH Alert: preventing injuries and deaths of 

fire fighters due to structural collapse. DHHS (NIOSH) Publication No. 99−146. http://www.cdc.gov/niosh/docs/99-146/ 

Training Materials and Additional 

Sources of Information

The National Institute of Standards and Technology, 

Building and Fire Research Laboratory’s Fire Research Division, maintains a website with links to publications on 

fire safety topics: http://www.fire.nist.gov/.

NIST [2003]. Early warning capabilities for fire fighters: 

testing of collapse prediction technologies [http://www.

fire.nist.gov/bfrlpubs/fire03/art072.html].

NIST [2003].Trends in firefighter fatalities due to structural collapse, 1979–2002. By Brassell LD, Evans DD. 

NISTIR 7069 [http://www.fire.nist.gov/bfrlpubs/fire03/

art024.html].

NIST [2003]. Structural collapse fire tests: single story, ordinary construction warehouse. By: Stroup DW, 

Madrzykowski D, Walton WD, Twilley WH. NISTIR 6959 

[http://www.fire.nist.gov/bfrlpubs/fire03/art093.html].

NIST [2004]. Structural collapse fire tests: single story, 

wood frame structures. By: Stroup DW, Bryner NP,Lee JH, 

McElroy JA, Roadarmel, GL, Twilley WH. NISTIR 7094 

[http://www.fire.nist.gov/bfrlpubs/fire04/art018.html]. 

Stroup DW, Bryner N [2007]. Structural collapse research at NIST. In: International Interflam Conference, 

11th Proceedings. Vol 1. London, England: Interscience 

Communications, pp. 593–604 [http://www.fire.nist.

gov/bfrlpubs/fire07/PDF/f07084.pdf]. 

NEHRP Consultants Joint Venture [2010]. Program plan 

for the development of collapse assessment and mitigation 

strategies for existing reinforced concrete buildings. NIST 

GCR 10-917-7. Redwood City, CA: NEHRP Consultants Joint Venture. Contract number B134107CQ0019 

for U.S. Department of Commerce, Building and Fire 

Research Laboratory, NIST [http://www.nehrp.gov/pdf/

nistgcr10-917-7.pdf].

Underwriters Laboratories maintains a website with information targeted specifically to fire fighter safety. Building 

construction materials, exposure hazards, ventilation practices and other topics that could influence structural collapse are covered: http://www.ul.com/global/eng/pages/

offerings/industries/buildingmaterials/fire/fireservice/

United States Fire Administration. 

http://www.usfa.fema.gov/fireservice/firefighter_

health_safety/safety/building_construction/
DEPARTMENT OF HEALTH AND HUMAN SERVICES

Centers for Disease Control and Prevention

National Institute for Occupational Safety and Health

4676 Columbia Parkway

Cincinnati, OH 45226–1998

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Solutions are based on research studies that show how 

worker exposures to hazardous agents or activities can 

be significantly reduced.

Preventing Deaths and Injuries to Fire Fighters by 

Establishing Collapse Zones at Structure Fires

DHHS (NIOSH) Publication No. 2014–120

April 2014