Firestorm 2007 - Houses burned from inside out

"And a lot of people saved their own homes"
"An untold number of homes were saved by people who refused to evacuate or sneaked back in to their neighborhoods before evacuations were lifted."

SAN DIEGO -- Something as seemingly inconsequential as a doggy door, a piece of particle board leaning against a garage door, or the holes underneath Spanish roofing tile may have made the difference between houses that burned and houses that were saved this year, it was reported Sunday.
A newspaper's analysis of the Witch Fire, the October conflagration that claimed 1,125 homes in San Diego County, shows that taking rigorous steps to close off the smallest openings in houses made as much difference as clearing brush in preventing a house from igniting in firestorms.
The Los Angeles Times analyzed construction records and fire behavior at houses burned in northern San Diego County last fall, and concludes that 75 percent of the burned homes had fire-resistant exteriors.
Unscreened vents, attic ventilators and broken windows -- even a doggy door -- apparently allowed streams of burning embers to blow into those houses, causing smoldering fires that ended with many homes erupting several hours after the fire front had already passed through, The Times reported.
The arched holes underneath Spanish roofing tiles were singled out by the state's top arson investigator as a particular trap for burning embers."I've seen houses with embers stacked in those openings," said Dave Hillman, chief investigator for Cal Fire. "I call them catchers' mitts," he told the paper.
Los Angeles County and other jurisdictions require those small archways to be sealed with grout, San Diego County does not, The Times reported.
The newspaper pointed out that an untold number of houses in Rancho Bernardo and other areas hit in San Diego County were saved by neighbors who had violated mandatory evacuation orders and stayed behind as the firestorm swept through. Those persons were able to put out small fires, or call for help, when houses ignited several hours after the main blaze had stormed through.
But firefighters said burned neighborhoods are extremely-dangerous, with destroyed houses smoldering, gas lines burning, and water lines out, officials said.
"Until it is safe, you don't allow people back in," said San Diego fire spokesman Maurice Luque. "We don't want to risk public safety for a house."Aggressive evacuation order enforcement was cited by law enforcement officers for the lack of fatalities and injuries in the massive fire that started with hellish Santa Ana winds on Oct. 21.

Full story at: LA Times