Authorities say the deadly fire at a ski resort bar in Crans-Montana, Switzerland, quickly developed right into a “flashover,” a harmful phenomenon in which all the things in a room ignites virtually concurrently.
The blaze rapidly grew right into a “flashover fire” after probably being attributable to sparklers in champagne bottles that got here too near the ceiling, Béatrice Pilloud, the lawyer basic for Valais canton, stated Friday.
A flashover happens when sizzling gases rise to the ceiling and unfold throughout the partitions, in accordance with the US-based National Fire Protection Association. The warmth then intensifies till all flamable objects in the room attain their ignition level and catch fire.
More background: Independent fire guide Stephen MacKenzie instructed NCS Friday a flashover creates ripples of smoke which unfold laterally throughout the ceiling and begin to “preheat” all the things in entrance of it.
As the fire spreads, it begins to hunt out extra oxygen, MacKenzie stated.
If a gap is made to confess oxygen — reminiscent of a door being opened as individuals attempt to escape — this might have created a “chimney effect,” he stated, which accelerated the circulate of smoke and flamable gases upward.
The fire can even have generated a mixture of flamable gasses, MacKenzie stated, which can begin to ignite. (*40*) he stated.
Asked how lengthy it takes a flashover to develop, MacKenzie gave a grim forecast. “Seconds,” he stated. “We’re looking at seconds to minutes.”