Winter Hazards

In 1927, on the coldest day in 50 years in New York City, units were battling a third-alarm fire in a seven-story commercial building on the waterfront. It was an exterior attack including the use of three fireboats, so it is reasonable to assume that much water was used. The fire was subdued, and command chiefs were discussing releasing units as two hose crews entered the building to finish off the fire and start overhauling.

Suddenly, the roof collapsed. Four firefighters were killed, and four others were injured. The cause of the collapse was the buildup of ice on the roof and walls and water absorbed by stock. There is no mention of any disciplinary or corrective action. That was then. This is now. It is very possible that an incident commander (IC) who sent personnel into such a building today would be subject to criminal prosecution and civil lawsuits and the department would be subjected to civil fines. NO roof is built to survive the load of firefighting operations added to a load of ice. Three Chicago firefighters died when they cleared away heavy ice to open a roof vent hole. As they went to open another hole, the roof collapsed. We must ever be attentive to undesigned loads on the roof and the fact that ventilation increases the fire attack on the structure.1


The following scene takes place in an architect’s office:

Senior: “Why all this reinforcement of the roof?”

Junior: “Sir, the roof is used by firefighters to ventilate the fire. It might be loaded with ice in the winter.”

Senior: “Take this note to the cashier, and get your final pay.”

We must understand buildings and the effects of fire on buildings. We must look out for ourselves. “No building is worth a firefighter’s life,” FDNY’s Deputy Chief (Ret.) Vincent Dunn has said many times.


Ice Underfoot

Plan for sand to be delivered to the scene as soon as a working fire is declared in freezing weather. Much ice results from leaking couplings. Take steps to eliminate leaks.

Stack Effect

Winter stack effect can deliver smoke and gases from a fire on the lower floors to the upper floors of a tall building. Locate the fire before you commit resources. Irritating smoke particles may drop out, leaving colorless, odorless, and tasteless CO in toxic quantities. Units searching upper floors should carry a CO detector and be prepared to assist unconscious victims.

On a cold day in New York City, a fire occurred in a fourth-floor apartment in a 22-story high-rise apartment building. Dispatch reported to the IC a fire on the fourth floor of a high-rise. Reports of smoke were received from the following locations:

Apt. 12: “Henry” reporting people trapped.

Apt. 14: “George” reporting people trapped.

Apt. 11: “Edward.”

Apt. 18: “Frank.”

Apt. 17: “Adam.”

Penthouse D: on the balcony.

Apt. 15: “Frank.”

Apt. 11: “Frank”-elderly female, difficulty breathing.

Apt. 18: “Robert”-female difficulty breathing.

Penthouse A & B.

Apt. 20: “Charlie.”

Apt. 10: “Frank.”

Note that the fire was on the fourth floor, but the smoke caused distress on floors from the 10th floor to the penthouse, with little or no effect on the floors between the fire floor and the tenth. Why? The answer is the “stack effect.”

Two FDNY firefighters died of CO poisoning on the top floor of a high-rise building that had a fire in the basement. The elevator operator was found dead in the elevator.2

Prearrange for automatic rehab assistance on working fires.


Lieutenant Louis Vercelli of the Villa Park (IL) Fire Department wrote the following:

    After reading your materials for as long as I can remember, I can finally say that I have seen some actual examples of how you saved my butt.

        A quick rundown: We were called to the scene of a fire in an abandoned Denny’s restaurant. On arrival, there was heavy smoke, and it had a very strong push. As my engineer located his water source, my ‘back seater’ and I did a walk-around. We could see no fire anywhere, but we knew it was well established. These buildings have huge void areas, and I assumed much of the fire was up there. Opening a mysteriously unlocked door in the rear, we found heavy smoke (“black fire,” as our colleague Dave Dodson calls it) to the floor. My first thought was, “It just isn’t worth it.” We went defensive right away, and guess what? Everybody went home to their families after shift. It’s a great thing.

        I am attaching a picture of one of the walls, which is pushed out significantly, most likely caused by the elongation of a steel bar joist (photo 1

      The mention of dense smoke and steel bar joists led me to ask him about the roof covering. As I suspected, it was a so-called “built-up roof,” and the fire undoubtedly was a combustible metal deck roof fire. I discovered this problem in 1946, and I proved the tactical solution in 1948: Cool the underside of the roof from a safe location. You freeze the tar, cutting off the gas flow through the joints in the corrugated steel.3

      In this case, since the roof could not be hit because of the ceiling, and since the building was abandoned, it was absolutely correct for the units to go defensive. Do not even think of venting such a roof. An adequate vent is much too large for manual operations, and firefighters are in mortal danger of a collapse without warning. Elongating steel pushed down a wall in a fire in Dallas, Texas, causing six firefighters to fall into the fire. Dense smoke at a CMDR fire in an Atomic Energy Commission plant at Paducah, Kentucky, forced a guard officer, an experienced firefighter, to jump through a process hole, knowing he would drop 24 feet to the floor.4

      John Novak’s excellent article “Challenges in Preengineered Metal Roof Decks of Polyiso Foam” (Fire Engineering, October 2004, page 65) reveals his understanding of the CMDR hazard.


      I realize that the question posed in “Strip Mall Fires” Parts 1 and 2 (Roundtable, September and October 2004) was about the choice of hoselines; however, the first question should be, “Is this building SAFE FOR INTERIOR OPERATIONS?” Several of the responders had referenced structure safety, particularly not operating on or under a bar-joist roof.

      If proper preplanning was done and the building was found to have a bar joist roof support system and a built-up roof, the fact is that a fire big enough to require a hoseline would doubtless heat the underside of the steel to 800°F for five minutes, making a combustible metal deck roof fire a certainty. Get out and look at commercial roofs. If the structure has bar joists and a built-up roof, the SOP should be DOA (Defensive on Arrival).

      If the roof construction is unknown, pull the first available ceiling to see if there are bar joists. See if the roof is a built-up roof by looking from an aerial apparatus. Given a body of fire in the rear, a gas fire will be burning up in the trusses, and you have now seen the deadly result. A multiversal stream from outside the collapse zone (elongating steel may bring down a wall) is recommended; it should be directed at the underside of the roof to cool the steel decking and thus cut off the gas flow. A tower ladder can do this very well. Keep it going. If you divert the stream, the fire will come back (based on my experience in 1946). Set up a second line to hit the main body of fire.5

      If you have had experience attempting to cool the underside of the roof deck to cut off the gas flow and found it did not work because it was a double roof and fire was between the void between the roofs, I would like to hear about it. Contact me at

      • • •


      I am writing this on my 86th birthday, the start of my 63rd career year. I would like a special birthday greeting from everyone who participated in the October Roundtable. The card should read as follows: “I have opened, selected the March 2001 issue, scrolled down to page 152 (your Ol’ Professor column), and saw the photo of a combustible metal deck roof that collapsed in a strip mall from which 20 firefighters had been evacuated 60 seconds before the collapse. I now realize that firefighters do not belong on or under a burning combustible metal deck roof. I have downloaded the article and distributed it. Our department is setting up an SOP for Combustible Metal Deck Roofs.” Send the “greeting” to


      1. The story of the Fire Department of New York tragedy is drawn with permission from page 65 of the Millennium edition of The Bravest, published in 2000. This edition is out of print; an updated publication may be obtained by calling (212) 698-4524.

      2. See Building Construction for the Fire Service, Third Edition (BCFS3), pages 481-485, for a discussion of winter stack effect and its opposite, summer stack effect.

      3. BCFS3, 302-309.

      4. The story of the CMDR that collapsed 60 seconds after 20 firefighters were evacuated is included in Ol’ Professor, March 2001. To access the archives, go to, click on “search options,” select March 2001, and scroll down to Ol’ Professor. For a list of which Fire Engineering issues contain my columns, contact me at

      5. This hazard is fully discussed in BCFS3, pages 302-308.

      6. All who write will be sent by e-mail “Disaster on Broadway,” a gripping story of a disaster caused by incompetent orders, written by the first-due chief’s aide.

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