Water has been restored to hundreds of customers affected by a water main break Wednesday morning in Hayward, a city Department of Public Works employee said.

The department was alerted about water coming up from beneath the pavement at West Jackson and Santa Clara streets just before 4 a.m., said Alex Ameri, director of utilities and environmental services at the Department of Public Works.

Crews responded immediately and excavated the sidewalk until they reached the leak, he said.

Two 12-inch pipes were uncovered, including a 1927 cast-iron pipe that runs down Jackson Street and a 1958 asbestos-cement pipe that runs north on Santa Clara Street, Ameri said.

The 1958 pipe was the one that ruptured, he said.

Water was shut off to the commercial and residential customers in the area until about noon.

Ameri said some nearby restaurants closed Wednesday morning because of the lack of water, while the Lucky Supermarket, located at 25151 Santa Clara St., remained open and had water.

Around 2:45 p.m. repair crews completed their work. Two lanes of eastbound Jackson Street that had been closed were able to reopen then, Ameri said.

A section of the cement pipe was replaced and has prompted the water department to check if similar cement pipes need to be replaced.

He said the cement pipes are often more prone to leakage and problems.

Wednesday morning's rupture appears to be caused by heavy rains saturating the soil in the past few weeks and the recent drop in temperature.

He said throughout the city there have been several smaller leaks in the cold weather.

Wednesday's break was "the biggest one we had seen" and "very prominent," he said.