Hundreds of thousands of gallons of raw sewage were dumped into Santa Monica Bay when one of the largest pipelines in the city's sewer system became blocked, officials said.

Public health officials were expected to order the closure of beaches from Venice Pier to El Segundo, a seven-mile stretch of Southern California coastline, said Anna Sklar, a city Bureau of Sanitation spokeswoman."We're talking minimally hundreds of thousands of gallons, possibly even millions," Sklar said. "This is a biggie.

"It's clear that because of the contamination that occurred at the beach, that the line was blocked for several hours and maybe for a couple of days," she said.