CALIFORNIA: The flooding and mudslides, affecting areas scorched by wildfires last month, have shut down more than 30 miles (48km) of the main coastal road.
Emergency services said a number of people were unaccounted for and they expected the number of deaths to rise.
Thousands fled the deluge and more than 50 rescues have been performed. The hardest-hit homes were those that were not in the evacuation zone, officials say.
Heavy rain run-off caused a mudflow in the community of Montecito, where some homes were knocked off their foundations, said Santa Barbara County Fire Department spokesman Mike Eliason.
Boulders the size of small cars was rolling down hillsides and blocking roads, reports BBC News Los Angeles correspondent James Cook.
Among those taken to safety was a 14-year-old girl who had been trapped for hours in the ruins of her home. The fire department published a picture of the girl encased in mud as she was led to safety.
The US Coast Guard has sent “multiple airships to support rescue operations” and warned the public not to fly drones, otherwise the flights would be grounded.
Thousands of California residents were asked to leave their homes on Monday for the second time in two months.
In Burbank, where waves of mud swept away vehicles, officials issued a mandatory evacuation order. Homeowners in the area shared photos of mud in their homes.
Several roads are closed, including the major Highway 101.
Wildfires in December, including the Thomas Fire, swept through the area burning vegetation that helps prevent flooding and landslides.
After a wildfire, burned vegetation and charred soil create a water repellent layer which blocks water absorption and leads to an increased risk of mudslides and floods.
“Recent burn areas will be especially vulnerable where dangerous mud and debris flows are possible,” said the National Weather Service in a statement.
