A hydrant damaged in a car crash sent water and mud streaming onto streets and hillsides Wednesday morning in a Hollywood Hills neighborhood.
The break was reported around 12:40 a.m. in the 8400 block of Grandview Drive, according to the Los Angeles Fire Department. The broken hydrant caused significant debris to flow down the hillside and onto Sunset Boulevard at Kings Road, firefighters said.
Mud piled as high as 5 feet in some locations.
Part of one of the homeowners' backyards collapsed as a result of the flowing water. Ferraris, Maseratis and other cars were surrounded by mud, but no significant damage to homes was reported.
Water was shut off to the area.
"Who knows that's going on underneath the ground," said resident Mark Fraser.
Cleanup is expected to continue into Wednesday evening. Engineers and geologists examined the hillside Wednesday morning to determine whether it had stabilized.
Jonathan Lloyd and Michelle Valles contributed to this report.