Heavy overnight rain sent mud flowing onto the Pacific Coast Highway, leading to a full shutdown of the highway between Malibu and Santa Monica Friday, authorities said.

The second in a pair of back-to-back storm systems moved across Southern California overnight, triggering small mudslides in the Palisades Fire burn area and keeping public works crews and first responders on alert.

A mudslide occurred overnight on Pacific Coast Highway just north of Big Rock Drive, covering all lanes of the roadway — which was closed at the time as a storm precaution. Caltrans officials said crews were examining the damage, and it was unclear how long it would take to clear the road.