Point of ignition

As the doors closed, the room darkened. Not from a lack of light — the raging fire 10 feet in front of them and barely above their heads provided enough of that — but from charcoal gray smoke descending to the floor.

Newport Beach firefighters had no where to go with the flames and smoke quickly engulfing them, so they did what they were trained to do: shoot down the flames with bursts from their hose.

Monday night nearly a dozen Newport Beach firefighters got their annual lesson on the signs of “flashover,” a phenomenon firefighters face when a fire is growing, but has not fully developed. When smoke — unburnt fuel for the fire — accumulates from the ceiling to the floor and the room grows hotter, up to the ignition point at 1,200 degrees, the smoke, creeping above the firefighters’ heads, instantly turns to flames.

The firefighters are only feet below the fire, where the temperature is a “comfortable” 400 to 500 degrees. Expert firefighters reminded the more inexperienced ones of the signs of an imminent flashover and how to stave one off by cooling the room.

Flashovers are usually fatal, killing anyone, including firefighters in full protective gear.

— Joseph Serna