Some 27,000 residents have been forced to flee their homes in the middle of the night as a rapidly spreading wildfire rips through southern California.
Nearly 8,000 homes were under mandatory evacuation in Ventura County, north of Los Angeles.
Firefighters warned that the fire was moving so fast they were unable to contain it.
The fire, known as the Thomas Fire, has already caused at least one death and power outages throughout the area as it burns through dry brush.
The blaze started on Monday evening and by early Tuesday had burned 26,000 acres (10,500 hectares).
One motorist was killed in a traffic accident while trying to flee the fire, officials said.
More than 250,000 homes are without power and at least two buildings, including a large apartment complex, were destroyed.
"We got my kids out first," Melissa Grisales told ABC 7 in Los Angeles.
"Pretty scary, really. I didn't think it was going to come to that, but I am starting to get pretty concerned."
About 500 firefighters are battling to protect structures from the fire, county officials said, while emergency workers were going house to house to tell people to leave their homes.
But Ventura County Fire Chief Mark Lorenzen said: "The fire growth is just absolutely exponential.
"All that firefighters can do when we have winds like this is get out ahead, evacuate people, and protect structures."
California wildfires cause thousands to flee, in pictures
Evacuation centres have been opened in schools and fairgrounds.
The fire is believed to have broken out close to Thomas Aquinas College in Santa Paula, some 50 miles north of Los Angeles, early on Monday evening.
About 390 students at Thomas Aquinas College were evacuated as a precaution, the school said on Twitter.
Strong eastern winds up to pushed the fire toward the cities of Santa Paula and Ventura, where about 140,000 people live, county officials said.
It is not the first time the state has been badly hit by wildfires in recent months - at least 40 people were killed when fires ripped through parts of northern California's wine region in October.