The Dangers of the “FIRE ATTACK STAIR”
Although extremely rare, in the event of an actual fire emergency the Philadelphia Fire Department will designate one or more of the fire exit stairways as the “Fire Attack Stair”.
This is the stairwell where firefighters advance their hose onto the fire floor. The door must be propped open to protect the hose line (which is stretched from the floor below), thus compromising the stair shaft as it rapidly fills with smoke and fire gases. As a result, this stairwell cannot be used to evacuate building tenants due to smoke conditions. Tenants descending from the building's upper floors suddenly will find themselves in a potentially life-threatening situation, if they remain in this stairwell.
It is therefore extremely important that tenants follow the instructions that are provided over the public address system during the course of an emergency. BUILDING STAFF, WORKING UNDER THE DIRECTION OF THE PHILADELPHIA FIRE DEPARTMENT WILL INSTRUCT TENANTS WHICH FIRE EXIT STAIRWAY IS SAFE FOR USE TO EVACUATE THE BUILDING. .
Key Concepts:
- In a major fire, smoke will migrate for at least several floors. It will rise until it cools, stratifies and levels off, or it may rise to the top of the shaft by way of the building's natural vertical draft.
- The most common gases in any fire are carbon dioxide (CO2) and carbon monoxide (CO). CO is the gas that causes most fatalities in fires. It is colorless, odorless, tasteless, flammable, toxic and also is lighter than air. There are numerous other toxic gases given off by burning plastics and foams that are even more deadly, but CO is the most common killer.
- In addition to smoke impeding the evacuation of building tenants, there also is a significant amount of congestion at the stair landing where the fire is being attacked. Firefighters, their tools and long hoses make that area nearly impassible. Tenants will be re-routed to the opposite stair for safe evacuation or relocation.
