Sonoma: Firefighters facing a resurgence of high winds struggled to halt wildfires that have killed at least 23 people, destroyed 3,500 structures and left hundreds missing in chaotic evacuations across northern California`s wine country.
Nearly two dozen blazes spanning eight counties have charred around 170,000 acres (68,797 hectares). Flames erupted on Sunday night when gale force winds toppled power lines across the region, possibly igniting one of the deadliest wildfire outbreaks in California history.
Flames were spread rapidly by hot, dry "Diablo" winds - similar to Southern California`s Santa Ana winds - that blew into northern California toward the Pacific on Sunday night.
The official cause of ignition has not been determined. But electric wires knocked down by those same winds may have sparked the conflagration, according to Daniel Berlant, spokesman for the California Department of Forestry and Fire Protection (Cal Fire).
"That is definitely a possibility," he told Reuters. "Power lines are a common cause of fires during wind events."
Berlant said some of the victims in northern California were asleep when the fast-moving fires broke out, igniting their homes before they could escape.
At least 20,000 people remained under evacuation as the fires raged largely unchecked for a third day, belching palls of smoke that engulfed the region and drifted south over the San Francisco Bay area, where some residents donned face masks.
The entire town of Calistoga, a Napa Valley community of some 5,000 residents spared from advancing flames the first night of the fire, was ordered to evacuate on Wednesday evening, as the county sheriff`s office warned that conditions had worsened.
More than 550 people were still reported unaccounted for in Sonoma County on Wednesday morning, said Jennifer Laroque, a county emergency operations center spokeswoman.
It was unclear how many of the missing might be actual fire victims rather than evacuees who merely failed to check in with authorities after fleeing their homes. Officials urged displaced residents to let their family members know they were safe.