Entering Through the Door, Falling Through the Floor

Nov. 19, 2008
The Underwriters Laboratories recently conducted a series of six tests where mannequins were positioned on floors and roof assemblies with fire burning below them and the collapse conditions were not what was expected.

The concern about the poor performance of the engineered lightweight wood construction under fire conditions is nothing new. We have known about it for more than a couple of decades. Obviously, the very first name that comes to mind when talking about this subject is the legendary Francis Brannigan, and his famous Building Construction for the Fire Service book.

There are many great reports, but just a handful of them are mentioned here. Back in 1992, United States Fire Administration (USFA) did a report, titled "Wood Truss Roof Collapse Claims Two Firefighters (December 26, 1992)"; National Institute for Occupational Safety and Health (NIOSH) did a report on April 2005 titled "Preventing Injuries and Deaths of Firefighters due to Truss System Failures"; National Institute of Standards and Technology (NIST) did a report in January 2007 titled "A Study of Metal Truss Plate Connectors When Exposed to Fire".

Through his writings and all his presentations, Brannigan tried for years, to teach us about the importance of having a good working knowledge of building construction and repeatedly advised us to "know your enemy". We in the fire service though, have not fully grasped the concept yet; at least not as well as we should. This year, it seems that there wasn't a month passing by, that we did not hear about firefighter fatalities and injuries resulting from catastrophic structural failures under the fire conditions.

On April 4, 2008,veteran Colerain Township, OH, Fire Capitan Robin Broxterman, and Firefighter Brian Schira were killed in the line of duty when they fell through the first floor of a working house fire. The fire was in the basement of a two-story, four bedroom house built in 1991. Reports indicate that the alarm came in shortly after 6:00 a.m.

Captain Broxterman and firefighters Kenny Vadnais and Brian Schira went into the burning building. Three went in, but only one came out. Firefighter Kenny Vadnais believes he is alive today because Robin and Brian helped him escape the fire's death grip. No other injuries were reported. And the two occupants of the house made it out before the firefighters arrived on the scene.

When a firefighter dies in the line of duty, NIOSH will respond and conduct an investigation into the event. NIOSH's intent is not to find fault or lay blame. Their intent is to learn lessons from the mistakes, or events, and to release a report with the results of their investigation. The report is a public document and the fire departments are encouraged to review the report and learn from the events that led to the firefighter's death.

To get a perspective of the real world performance, and its effect on the firefighters' safety, let's look at two relatively recent incidents investigated by NIOSH. Below are the summaries of these two reports and the recommendations published as a result.

Incident 1: "Volunteer Fire Fighter Dies After Falling Through Floor Supported by Engineered Wooden-I Beams at Residential Structure Fire - Tennessee"

On Jan. 26, 2007, a 24-year-old volunteer firefighter died at a residential structure fire after falling through the floor which was supported by the engineered wooden I-beams. The victim's crew had advanced a handline approximately 20 feet into the structure with zero visibility. They requested ventilation and a thermal imaging camera (TIC), in an attempt to locate and extinguish the fire.

The victim exited the structure to retrieve the TIC and when he returned, the floor was spongy as conditions worsened which forced the crew to exit. The victim requested the nozzle and proceeded back into the structure within an arm's distance of one of his crew members who provided back up while he stood in the doorway. Without warning, the floor collapsed sending the victim into the basement. Crews attempted to rescue the victim from the fully involved basement, but a subsequent collapse of the main floor ceased any rescue attempts. The victim was recovered later that morning.

NIOSH investigators concluded that, to minimize the risk of similar occurrences, the fire departments should:

  • Use a thermal imaging camera during the initial size-up and search phases of a fire
  • Ensure firefighters are trained to recognize the danger of operating above a fire and identify buildings constructed with trusses or engineered wood I-beams
  • Consider modifying the current codes to require that lightweight trusses are protected with a fire barrier on both the top and bottom

Incident 2: "Career Engineer Dies and Fire Fighter Injured After Falling Through Floor While Conducting a Primary Search at a Residential Structure Fire - Wisconsin"

On Aug. 13, 2006, a 55-year-old career engineer died and another firefighter was injured after falling through the floor at a residential structure fire. The victim and the injured firefighter had arrived in their ambulance and assisted the first-due engine attach a 5-inch supply line at approximately 12:27 p.m. The engine company was conducting a fast attack on a suspected basement fire, while a ladder company conducted horizontal ventilation.

The ambulance crew had advanced to the front of the structure when the incident commander requested them to conduct a primary search. The victim and the injured firefighter proceeded to conduct a left hand search at approximately 12:34 p.m. They took a couple of steps to the left, just inside the front door, to conduct a quick sweep. Visibility was near zero, with minimal heat conditions. Because of the smoke conditions, they kneeled, sounded the ceramic tile floor, and took one crawling step while on their knees. They heard a large crack just before the floor gave way, sending them into the basement. The basement area exploded into a fireball when the floor collapsed. The victim fell into the room of origin while the injured fell on the other side of a basement door into a hallway. The injured firefighter was able to eventually crawl out of a basement window. The victim was recovered the next day.

The NIOSH investigators concluded that, to minimize the risk of similar occurrences, fire departments should:

  • Conduct pre-incident planning and inspections of buildings within their jurisdictions to facilitate development of safe fireground strategies and tactics
  • Use a thermal imaging camera during initial size-up and search phases of a fire
  • Ensure firefighters are trained to recognize the danger of operating above a fire and identify buildings constructed with trusses
  • Consider modifying the current building codes to require that lightweight trusses be protected with a fire barrier on both the top and bottom.
Three lessons should be taken from these two reports.
  1. These types of dangers impacts all firefighters, regardless if you are a career or volunteer. Fire does not know the difference, nor does it care, it is an equal opportunity killer.
  2. Both reports emphasized the importance of firefighters knowing the dangers of operating over a fire, and identifying buildings with trusses.
  3. Both reports recommend that the fire departments should modify the current building codes to require that lightweight trusses be protected with a fire barrier.

During the recent International Code Council's (ICC) Final Action Hearings in Minneapolis, for the 2009 edition of the building construction codes, by actively participating in modifying the deficiencies in the current building codes, the fire service attempted to address lesson three. There was a code proposal that would have required lightweight construction in residential properties to be protected with a 30-minute barrier.

The attendance at the Final Action Hearings set a record in the number of fire service attendees. The majority of those attendees were there to support the proposed requirement of residential fire sprinklers in one- and two-family homes. As you know, that proposal passed with a strong 73 percent majority, receiving 1,282 votes.

The proponents of the code change to require the protection of lightweight construction were hopeful of success due to the large fire service attendance. Another encouraging sign was the fact that the code change to require the barrier was scheduled to be heard immediately following the residential fire sprinkler proposal. Surely the fire service would remain to vote on such a critical safety issue.

Unfortunately, during the debate on the code proposal for the protection of lightweight construction we could see large numbers of firefighters leaving the room. In the subsequent vote, the proposal requiring the fire barrier received a majority of the votes, yet fell 50 votes shy of the required two-thirds majority required to be accepted into the codes. The proposal received over 700 votes. That means approximately 500 firefighters left the room after the sprinkler vote.

We were not as coordinated and organized as we should have been, and the fire service attendees were not well informed about the code hearing process and procedures. As a result, they believed that their work was successfully done and there were no more fire-related proposals to be voted on, so it was time to leave; just as they are used to returning to the fire station, right after responding to an incident and putting out the fire. But if only 60 firefighters would have stayed for the vote, we could have passed the requirement to protect lightweight construction. Exactly what NIOSH had recommended numerous times.

We will not give up our efforts to protect our firefighters. The fire service will be back in force, and we will be much better organized and more prepared. We are in it for the long run. In March 2009, another code proposal will be submitted in the ICC code process attempting to address this issue once again at the Code Action Hearings in October 2009 in Baltimore.

But remember that all these efforts would only enhance safety in the new houses being built in the future, and will not have any impact at all on the exiting homes. Now let's take a look to see what we in the fire service can and must do, to reduce our firefighter fatalities in the existing homes. That is especially important when you consider that there is an inventory of more than 100 million existing homes around our country and a majority of those built in the last 20 years were constructed with those lightweight wood trusses.

Then the question to be asked from the fire service leadership is: what can we do to reduce our firefighter fatalities resulting from such structural failures?

As a rule, in the fire service "we risk a lot to save a lot, and risk a little to save a little". Looking at it from the firefighters' safety perspective then, we do have the option of staying out, and to provide the exposure protection in a defensive mode of operation. This concept, even though contrary to our current aggressive interior attack mode of operations, is a very viable option that fire service should seriously consider. Simply stated, when it comes to the lightweight wood truss construction, it might be best to stay out from the get go, and protect our own firefighters.

Considering our professional obligation and deep commitment in the fire service to saving lives, this might be a lot easier said than done. And we don't have the slightest ambiguity that we would still be charging in full force, if we believe that someone might be trapped inside and a life could be saved. But then we should also remember our commitment is to save lives, and that also includes our own.

Simply stated, since these houses are built without much fire resistive rating and no active fire protection systems at all; we should not be risking firefighters' lives and must stay out, if there are no civilian lives to be saved in the first place. Buildings are disposable, lives aren't; and that goes the same for our firefighters' lives too.

To get a clear picture of why we should stay out and keep our firefighters safe when there are no lives to be saved, take a look at the latest Underwriters Laboratories (UL) report released on October 1, 2008. Last year, UL received a fire grant from the Department of Homeland Security to do a research study on the performance of the lightweight construction under the fire conditions. UL conducted a series of tests, and just this month posted the results of their study titled "Structural Stability of Engineered Lumber in Fire Conditions" on their UL University website.

This is a great online course that is free of charge and available to all. This course is essential for all firefighters and an absolute must for all incident commanders and fire safety officers across the land. It is only 52 minutes long, but it is absolutely worth it. Please take the time to educate yourself and the staff under your command. The lives that they save could be their own.

Just to give a brief overview, UL did six tests and videotaped them all. They had two firefighter mannequins in full gear with TICs on these test floors and roof assemblies. Watch the videos and see if you can predict when the mannequins will fall through.

It is also interesting to see the difference in the temperature reading of the TIC at the top assembly compared to the inferno below. In one test, after five minutes, the TIC temperature showed a comfortable 73 degrees on the floor level above the fire, while below the temperature was 1,378 degrees. Not that the TIC was not working or reading inaccurate temperatures, but the flooring and carpets do not transfer that temperature, so the TIC doesn't see it.

Briefly stated, based on this report the lightweight construction, the increased fuel load and the synthetic petroleum based materials all contribute to much greater fire growth. And needless to say, the faster fire growth significantly increases the probability of sudden catastrophic structural failure in these buildings. Time is working against us when fighting fires, and delayed response times could have direct adverse impact on the outcome of the call. The fact of the matter is that time is actually what we don't have as a luxury, when responding to these lightweight construction fires and catastrophic structural collapse and firefighter fatalities could be the end result.

Take a look at the "Time versus Products of Combustion" illustration posted on the United States Fire Administration (USFA) website and you can clearly see that the increase in time directly correlates to the magnitude of fire, and significantly increases the hazards facing our firefighters. This USFA illustration underlines the impact of response time, and also the importance of residential sprinklers in early suppression of fires.

It is positive to see that slowly, but surely the fire service is finally realizing the importance of their active participation in the code development process. This participation will not only protect our communities and provide for the safety of our citizens, but also our own firefighters putting their lives on the line day in and day out. Organizing the fire service to actively participate in the code development process is our task, as identified by Strategy 5 of the Vision 20/20 National Strategies for Loss Prevention which is focused on this very important issue.

We were successful in getting the residential fire sprinklers into the codes, which was a big gain, but then failed to get the 30-minute lightweight construction protection. We will keep on fighting for it and will undoubtedly succeed in future. We owe it to Robin Broxterman and Brian Schira, and all of our other brothers and sisters who gave their lives fighting the fires.

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AZARANG (OZZIE) MIRKHAH P.E., CBO, EFO, MIFireE, a Firehouse.com Contributing Editor, is the Fire Protection Engineer for the City of Las Vegas Department of Fire & Rescue. Ozzie served on the national NFPA 13 Technical Committee for Sprinkler System Discharge Design Criteria and serves on the IAFC Fire Life Safety Section Board of Directors. He was the first recipient of the IAFC's Excellence in Fire and Life Safety Award in 2007. To read Ozzie's complete biography and view his archived articles, click here. Ozzie has participated in two Radio@Firehouse podcasts: Six Days, Six Fires, 19 Children and 9 Adults Killed and Fire Marshal's Corner. You can reach Ozzie by e-mail at [email protected]. SEAN DeCRANE, is an 18-year veteran of the Cleveland Fire Department, where he serves as a battalion chief and an adjunct instructor for the Cleveland Fire Academy with an emphasis on continuing education. He currently holds a certification as an Ohio Fire Life Safety Inspector and also represents the International Association of Fire Fighters in the International Code Council's code process. Sean also serves on the Steering Committee for Vision 20/20: The National Fire Loss Prevention Agenda and is the lead contact for Strategy 5: Fire Fighter Participation in the Building Codes and Standards.You can reach Sean by e-mail at [email protected]

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