At least 13 people have been killed and homes torn from their foundations in flash flooding in southern California.
Downpours sent mud and boulders roaring down hills stripped of vegetation by a gigantic wildfire that raged in the state in December.
Rescue crews used helicopters to pluck more than 50 people from rooftops because trees and power lines blocked roads, dozens more were rescued on the ground and firefighters pulled a mud-caked 14-year-old girl from a collapsed Montecito home where she had been trapped for hours.
"I thought I was dead for a minute there," the girl could be heard saying on video posted by KNBC-TV before she was taken away on a stretcher.
Most deaths were believed to have occurred in Montecito, a wealthy enclave of about 9,000 people northwest of Los Angeles that is home to such celebrities as Oprah Winfrey, Rob Lowe and Ellen DeGeneres, said Santa Barbara County spokesman David Villalobos.
At least 25 people were injured and others were unaccounted for.
The mud was unleashed in the dead of night by flash flooding in the steep, fire-scarred Santa Ynez Mountains.
Burned-over zones are especially susceptible to destructive mudslides because scorched earth does not absorb water well and the land is easily eroded when there are no shrubs.
The torrent of mud early yesterday swept away cars and destroyed several homes, reducing them to piles of lumber.
Photos posted on social media showed waist-deep mud in living rooms.
Flash flood / massive amounts of mud swept thru #montecito oaks neighborhood. Mud buckling doors trying to get in house. People on roofs. Power out. Power lines down all over #mudslide pic.twitter.com/1SvgOpqBTw— Benjamin Hyatt (@caffeineben) January 9, 2018
"I came around the house and heard a deep rumbling, an ominous sound I knew was ... boulders moving as the mud was rising," said Thomas Tighe, who discovered two of his cars missing from the driveway in the middle of the night."
"I saw two other vehicles moving slowly sideways down the middle of the street in a river of mud."
In daylight, Mr Tighe was shocked to see a body pinned by muck against his neighbour's home.
Authorities had been bracing for the possibility of catastrophic flooding because of heavy rain in the forecast for the first time in 10 months.
Evacuations were ordered beneath recently burned areas of Santa Barbara, Ventura and Los Angeles counties.
But only an estimated 10 to 15% of people in a mandatory evacuation area of Santa Barbara County heeded the warning, authorities said.
Some of the worst damage was on Montecito's Hot Springs Road, where the unidentified girl was rescued and residents had been under a voluntary evacuation warning. Large boulders were washed out of a previously dry creek bed and scattered across the road.
The worst of the rainfall occurred in a 15-minute span starting at 3:30am on Tuesday.
Montecito got more than a half-inch in five minutes, while Carpinteria received nearly an inch in 15 minutes.
Montecito is beneath the scar left by a wildfire that erupted Dec#ember 4 and became the largest ever recorded in California.
It spread over more than 440 square miles and destroyed 1,063 homes and other structures. It continues to smoulder deep in the wilderness.
The storm walloped much of the state with damaging winds and thunderstorms.
Downtown San Francisco got a record 3.15 inches of rain on Monday, smashing the old mark of 2.36 inches set in 1872.