Laguna Beach was digging out after heavy rains pummeled the area leaving in their wake mudflows that damaged downtown businesses and eroded the boardwalk.
Public works employees on skip-loaders were clearing streets, and police and firefighters were tallying up the damage, Laguna Beach police Lt. Jason Kravetz said.
Laguna Canyon Road was expected to be closed at least through Thursday, he said.
In a two-hour period beginning about 3 a.m., mud and debris flowing out of Laguna Canyon and into downtown inundated some businesses and piled up in front of the movie theater on Coast Highway at Broadway.
The rush of water also eroded part of the beach as it made its way to the ocean, running under the boardwalk.
About 6:40 a.m., a pedestrian was fatally struck downtown on Coast Highway, near Thalia Street, Kravetz said. The woman's name was not immediately released.
About 40 homes in Laguna Canyon were voluntarily evacuated. It was unclear if any were damaged.
Local news from across Southern California
At one point this morning, members of a swiftwater rescue team were using an inflatable boat to get around Laguna.
"It's quieting down now and we see some clearing," Kravetz said about 10:30 a.m. "The flooding has subsided."
Despite a break in the storm this morning, forecasters were warning that thunderstorms, hail and waterspouts were possible later Thursday.