The flames destroyed hundreds of homes, a hospital, a gas station, several restaurants and numerous vehicles in Paradise, officials said. The blaze, dubbed the Camp Fire, was driven by dry conditions and strong winds.
The flames spread so fast that firefighters could not be everywhere at once and residents took matters into their own hands.
The fire's cause remained under investigation but Southern California Edison reported to the California Public Utilities Commission that there was an outage on an electrical circuit near where it started as Santa Ana winds blew through the region.
In northern California, a wildfire killed some in their cars as they tried to flee the racing flames.
SoCal Edison said the report was submitted out of an abundance of caution although there was no indication from fire officials that its equipment may have been involved.
The Ventura County Fire Department said the blaze had burned around 8,000 acres (3,237 hectares) and evacuation orders were issued for some 88,000 homes in Ventura County and neighboring Los Angeles County. It was unclear how many homes have been evacuated within the City of Los Angeles.
And in Malibu, mandatory evacuations were ordered for the entire city, where about 12,000 people live, and is known for celebrity beachside homes. Ventura County Fire Chief Mark Lorenzen said some firefighters were "literally pulling people out of burning homes".
The Woolsey fire, located in Los Angeles County and Ventura County, is 70,000 acres in size.
Tens of thousands of people are displaced from their homes as these fires continue to rage.
The area has been contained, but due to the location, elements and hazards in the area because of the Woosley Fire, homicide detectives will respond to the scene Saturday, Moore said.