One of California's strongest storms in years - dubbed a "bombogenesis" or "weather bomb" - has hit the state, killing at least four people and bringing torrential rain and floods.
Power cuts hit 150,000 households and sinkholes swallowed cars.
Hundreds of homes were evacuated amid fear of mud slides near Los Angeles.
More gusts, heavy rain and flash floods are expected on Saturday but the storm is due to subside by Sunday.
More than 300 flights have been disrupted at Los Angeles International Airport, and major roads have closed.
One man was killed after a tree fell and pulled a power line on to his car in the Sherman Oaks area of Los Angeles.
A second person died in a vehicle when it was submerged by a flash flood in the town of Victorville.
Another motorist at the same junction was saved after climbing on to the roof of his car.
Two others died in car accidents in the San Diego area.
Ryan Maue, a meteorologist for WeatherBell Analytics, told the Los Angeles Times that 10 trillion gallons of rain would fall on California in the next week, enough to power Niagara Falls for 154 days.
Two cars fell down a sinkhole in LA neighbourhood Studio City, with the drama of the second one, teetering on the edge and then tumbling down, shown on live television.
Firefighters saved one person from the first car, and the driver got out of the second before it fell. No-one was injured.
Erik Scott from the Los Angeles Fire Department said that the sinkhole rescue was "a very unique and dangerous situation".
He said the frightened driver in the fallen car was forced to stand on top of her vehicle, underground and amid rushing water, until a ladder could be passed down to her, 10ft (3 metres) below the street.
The Los Angeles Times also spoke of "surreal scenes" with cars trapped by rising waters along freeways 11 and 15. The state's fire department said firefighters had to rescue 15 people from cars trapped in fast-moving water on a road in Sun Valley, and use ropes and inflatable boats to rescue seven people and two dogs from a flood-control area on the Los Angeles River.
Evacuation orders were issued in the city of Duarte, in the foothills of the San Gabriel Mountains east of Los Angeles, and in parts of Camarillo Springs in Ventura County.
It is feared that areas that have been previously hit by forest fires could be more susceptible to mud slides as there is less vegetation to break the flow of running water.
Terry Anzur of KFI News told the BBC the dry, scorched ground that had been "saturated" with the heavy downpour was turning streets in to "rivers of mud".
After five years of drought, a series of storms have filled state reservoirs.
In Duarte, about 20 miles (32 km) east of Los Angeles, city authorities said they had been door to door to issue mandatory evacuations.
Those who chose to stay were required to sign notifications.
One local, Alberto Moreno, told Reuters news agency that he was staying put. "The neighbours are here so we're all basically going to help out each other if it comes down to it," he said, while barricading his home with sandbags.
Meteorologists describe the "bombogenesis" as an intense extra-tropical cyclonic low-pressure area, or "a weather bomb".
"The storm looks to be the strongest storm to hit southwest California this season," the National Weather Service said.
"It is likely the strongest within the last six years and possibly even as far back as December 2004 or January 1995."
Gusts of 87mph (140km/h) were reported on the Big Sur scenic coastal highway.
Earlier in the week, heavy rain and melting snow caused fears of flooding at the tallest dam in the country, Oroville Dam, in northern California. More than 180,000 residents evacuated their homes.
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