Structural Collapse Guide


The Occupational Safety and Health Act (OSH Act) requires employers to comply with hazard-specific safety and health standards. In addition, pursuant to Section 5(a)(1) of the OSH Act, employers must provide their employees with a workplace free from recognized hazards likely to cause death or serious physical harm. Emergency Preparedness Guides do not and cannot enlarge or diminish an employer's obligations under the OSH Act.

Emergency Preparedness Guides are based on presently available information, as well as current occupational safety and health provisions and standards. The procedures and practices discussed in Emergency Preparedness Guides may need to be modified when additional, relevant information becomes available or when OSH Act standards are promulgated or modified.

Rescue Workers and Emergency Responders may already have experience with entering collapsed structures resulting from (1) construction catastrophes, (2) earthquakes, (3) fire and (4) weather related structural failures. Weather related structural failures typically result from rain/snow accumulations on roofs, hurricanes, tornadoes, landslides and even avalanches. Today, rescue workers and emergency responders also face the possibility of entering a structure that has collapsed following a terrorist attack. Terrorist activity may add additional hazards such as secondary devices, follow-on attack and residual radiological, biological or chemical contamination. Historically, terrorist activities that have resulted in collapsed structures include crashing commercial jets into the World Trade Towers in New York City (September 11, 2001) and vehicular bombs, such as the one used at the Murrah Federal Office Building in Oklahoma City, OK (April 19, 1995). Regardless of the root cause of the structural failure, rescue workers and emergency responders who enter a collapsed structure in order to perform their duties should work safely.

General Information
What is a collapsed structure?

When internal load bearing structural elements fail, a building will collapse into itself and exterior walls are pulled into the falling structure. This scenario may be caused by construction activity, an earthquake, or fire, and may result in a dense debris field with a small footprint. Alternatively, if the structural failure is caused by an explosion or natural forces such as weather, the building may collapse in an outward direction, resulting in a less dense and more scattered debris field.

Who enters a collapsed structure?
Rescue workers looking through debris

Following a catastrophic failure of a structure for whatever reason, rescue workers and emergency responders may be required to enter the collapsed structure. Emergency responders include firefighters, police, emergency medical technicians, construction workers and government representatives. Emergency responders may be responsible for assisting survivors, extinguishing fires, shutting off utilities, assessing structural instabilities, shoring up safe paths into the structure and assessing other hazards, such as airborne contaminants. Rescue workers such as Urban Search and Rescue Teams focus on finding survivors, and later removing victims from collapsed structures. In addition, many terrorist investigators will be on site treating the collapsed structure as a crime scene.

Organizing Rescue Workers and Emergency Responders
What is the organizational structure for the response to these events?

Although these catastrophic events may initially be quite chaotic, site management will eventually be under an Incident Command System. Local responders and rescuers will obviously respond first with the State requesting Federal Emergency Management Agency (FEMA) assistance if warranted.

A trained Structures Specialist from Urban Search and Rescue will be responsible for:

  • Evaluating the immediate structural condition of the area to be entered during rescue operations.
  • Determining the appropriate type and amount of structural hazard mitigation in order to minimize risks on site to rescue personnel.
What safety and health resources are available during a collapsed structure response?

Once the Incident Command System is established at a collapsed structure, the Incident Commander maintains accountability for all response personnel at the scene. A Safety Officer may also be mobilized and report directly to the Incident Commander. The Safety Officer is responsible for monitoring and assessing the safety aspects of the responders during the collapsed structure event. The Safety Officer's responsibilities may include:

Rescue worker with dog
  • Overseeing all safety and health aspects of response personnel
  • Assuring that optimal safety and injury prevention is practiced
  • Investigating and documenting all response team injuries and illnesses
  • Preparing and maintaining entry permits
  • Ensuring that appropriate personal protective equipment (PPE) is used
  • Developing and implementing daily health and safety plans which address (1) sanitation, (2) hygiene, (3) PPE, (4) Decontamination, (5) work/rest cycles, (6) acute medical care, etc.
  • Interviewing off-going shifts to assess developing hazards
  • Assessing risk for the identified hazards; and
  • Training in hazard awareness and use of PPE.
  • Assessing structural instabilities
What hazards may be encountered when entering a collapsed structure?

The following hazards should be considered to protect rescue workers and emergency responders when preparing to enter a collapsed structure:

Rescue workers and emergency responders
  • Water system breaks that may flood basement areas
  • Exposure to pathogens from sanitary sewer system breaks
  • Exposed and energized electrical wiring
  • Exposure to airborne smoke and dust (asbestos, silica, etc.)
  • Exposure to bloodborne pathogens
  • Exposure to hazardous materials (ammonia, battery acid, leaking fuel, etc.)
  • Natural gas leaks creating a flammable and toxic environment
  • Structural instability
  • Insufficient oxygen
  • Confined spaces
  • Slip, trip or fall hazards from holes, protruding rebar, etc.
  • Being struck by a falling object
  • Fire
  • Proximity to heavy machinery such as cranes
  • Sharp objects such as glass and debris
  • Secondary explosive devices left by terrorists
  • Secondary collapse from aftershock, vibration and explosions
  • Residual chemical, biological or radiological contamination
  • Unfamiliar surroundings
  • Adverse weather conditions
  • Noise from equipment (generators/heavy machines)
Additional Information