Swimmers and surfers were advised to avoid the water in the San Pedro Bay beach area until at least 5 p.m. Thursday.
The beach was shut down after a sewer line broke on Tuesday. Public health officials will test bacteria levels in the water, and once the levels are safe, the beach will be reopened.
Recorded information on beach conditions is available 24 hours a day at (800) 525-5662, and online at www.publichealth.lacounty.gov/beach.
City News Service contributed to this report.