A blowtorch of dry Santa Ana wind and blazing embers destroyed or damaged 36 expensive homes early Friday when a roaring 3,000-acre brush fire chased residents from their beds in a third day of destruction.

Police asked residents to evacuate threatened areas where many houses have fashionable but flammable wooden shingles, but officials did not know how many left. Schools were closed and evacuation centers were set up at campuses and a synagogue. No serious injuries were reported.The firestorm, driven by erratic gusts of up to 70 mph blasting off the desert, hit the northwestern San Fernando Valley, adding new destruction to the 22 homes lost and many others damaged Wednesday and Thursday, when the wind toppled trucks and knocked out power to half a million customers.

"We still face a very dangerous situation," Fire Chief Donald O. Manning said as the fire eluded control at midafternoon in non-residential lands close to other residential areas. "We're not out of the woods yet."

Thirteen homes were destroyed and 23 were damaged early Friday, said Fire Department spokesman Gary Svider, putting the loss at $3.9 million. Earlier, officials had said 22 homes were destroyed or damaged, but a closer look at the burned area resulted in the higher estimate.

The fire raced from Sunshine Canyon through the Santa Susana Mountains 25 miles northwest of downtown and down into the fashionable Porter Ranch development, said county fire spokesman John Lenihan.

Helicopters braved fierce turbulence that made it difficult to make water drops accurate, while vans carried ground crews up to the battle. Fire trucks stood guard around an oilfield.

Two firefighters were hospitalized for embers in their eyes, two suffered from inhaling fumes of chlorine from burning pool supplies, and 30 firefighters and one civilian suffered smoke inhalation, Manning said.