Flooding, mudslides and debris flows caused by the heaviest rain in Los Angeles and southern California in a year shut Pacific Coast Highway from approximately Santa Monica to the Malibu Pier.

On Friday, the storied coastal road had dissolved into a river of mud and debris after a powerful rainstorm sent those burned hillsides careening toward the ocean, turning canyons into rivers of mud and rocks.

Heavy rain battered Southern California on Thursday and made for dangerous conditions near burn scars from recent wildfires.

In the Los Angeles area, the burn scars that carry the highest risk are those from the Eaton and Palisades fires from January and the Bridge Fire from the fall.

As the downpour intensified Thursday, the National Weather Service issued flash flood and severe thunderstorm warnings for a swath of eastern Los Angeles County. The rain caused a rockslide and pushed mud onto the road in Malibu Canyon, and a large debris flow left about 8 inches (20 centimeters) of mud across a road in the Hollywood Hills.

A monster rainstorm was drenching southern California on Thursday, with officials in Los Angeles readying for flooding and landslides in areas burned by last month's huge wildfires.