Every firefighter fears getting trapped in a burning structure and being burned to death. No words can express or describe the very real fear we experience at every structural fire to which we respond.
One of the situations that can unfold is a rapid-fire event – or in the case of this month’s video, a flashover. A flashover can occur at any structure fire, not only once but multiple times under the right conditions. A flashover by layman’s definition is an event where unburned particles of combustion (black fire or black smoke) ignite rapidly or simultaneously. When ignition occurs, there is a rapid spike in temperature that is well beyond the limits of what our gear can sustain.
In our video this month, we witness a situation where a firefighter needed to escape the interior conditions quickly in order to avoid being caught in a flashover. Fortunately, the firefighter did not sustain any major injuries, only minor injuries that occurred during their rapid escape.
This video is a good example of how every firefighter must be aware of how the dominoes can line up, leading to a bad outcome. Once again, fortunately, the firefighter was able to recognize the signs of flashover and had enough time to escape.
The video highlights for us the signs of flashover from the exterior. At around the 2-minute mark, you will see from the Bravo side where one of the side windows is open. The window is broken out from the interior crews. Why they did this, we do not know. It’s possible that they were trying to vent the area or getting ready to get out.
[Read next: Horizontal ventilation and PPV: Back-to-basics tactics]
As the window is open, you will see thick, black, angry smoke exiting the structure. The smoke is moving with intensity and velocity. It is very turbulent, which indicates high heat. There is also a bilateral flow path being created because as the smoke is exiting the top and at the bottom, fresh air is entering the structure.
We cannot see the inside of the room, but it is safe to assume that the interior temperatures are increasing exponentially and visibility is zero at the floor right up to the ceiling, creating an environment that is untenable for the crews working inside.
The dominoes are lining up and leading us to the conclusion that a flashover is coming, and something needs to be done to either reduce that potential, such as rapid vertical ventilation and/or rapid cooling of the interior with water or getting out of the environment.
[Next resource: Vertical ventilation: A firefighter’s ladder-to-roof guide]
The firefighter decided it was better to get out of the environment first, then deal with the interior issue from a different approach.
Training time
After watching this video and reading this resource with your company, engage in the following training:
- Review the impending signs of flashover;
- Review other rapid-fire events, such as backdraft and smoke explosions, to learn the signs of impending danger; and
- Review and practice simple bailout techniques, like a first window exit or a head first ladder dive.
