In Sherman Oaks, a falling tree downed power lines and hit a car. A 55-year-old man was electrocuted and pronounced dead at a hospital, police and fire officials said.
Heavy rains turned creeks and rivers into brown torrents and released slews of mud from hillsides burned barren by wildfires. Several stretches of freeways and highways were closed by flooding.
In San Bernardino County, a 20-mile stretch of State Route 138 in the West Cajon Valley was closed at the scene of a summer wildfire.
Massive winter storm pounds SoCal
Mud sloshed over concrete rail barriers and about two dozen vehicles, including big-rigs and a school bus, were either mired in mud or became unable to turn around on the closed road and some were abandoned, county fire spokesman Eric Sherwin said.
A 75-foot tree crashed into a six-unit apartment building on Kelton Avenue in Westwood, narrowly missing a person. Officials red-tagged the apartments and evacuated 16 college students. No one was injured.
75-foot tree crashes onto building in Westwood
In Sun Valley, 10 cars were trapped in swift-moving water on a roadway, and eight people had to be rescued, the Fire Department reported.
Two people in a car were rescued and four students on the bus were removed and taken to a school office, he said.
The Associated Press contributed to this report.
Forecast: http://abc7.la/ABC7Forecast
Live radar: abc7.la/LiveMEGADOPPLER
Watches/Warnings: abc7.la/WxWarnings
Share your weather pictures and video with #ABC7Eyewitness