Utility Discloses Delay of Nearly 2 Hours in S.F. Power Failure

Pacific Gas & Electric Co. disclosed Tuesday that its workers had taken almost two hours to respond to a fire alarm at a major electrical substation and may have contributed to the severity of the resulting power outage last weekend, which blacked out about a third of the city and disrupted holiday shopping,

“We’re accepting responsibility for the fact that we did not respond as fast as we should have,” Jeff Butler, PG&E; vice president of operations, told a news conference at company headquarters. “Failing to immediately respond ... may have extended the duration of the outage.”

The company’s preliminary investigation into the power failure, which affected 120,000 customers, found that, for unknown reasons, alarms went unheeded after a distribution cable failed at 3:51 p.m. Saturday at the Mission Substation.

Officials said an audible alarm had immediately gone to the utility’s control center, and three seconds later a firm alarm indicator had appeared on the computer screen there. This initial circuit failure did not result in any customer outages because alternative power sources kicked in. But two more substation circuits failed about 5:30 p.m., triggering outages and customer calls.

PG&E; personnel arrived at the substation within 18 minutes.

The power failure at the unmanned substation knocked out power in homes, restaurants and stores across the city on Saturday, and into Sunday night for some.

Traffic lights were out at major intersections. Some people were stranded in elevators, and retailers lost business on what is one of the busiest shopping weekends of the year.

Butler said the investigation had not found any indication of sabotage or terrorism. He said a distribution cable had failed for unknown reasons and caught fire to trigger the outage.

He said more than one person staffs the control room in nearby Daly City and the utility was investigating the cause of the delay in the response.

“I don’t want to speculate on what occurred,” Butler said. “They may have received numerous alarms. This facility monitors the distribution system for all of San Francisco down to San Mateo.”

Damage claims by stores and others for the outage could be substantial.

A power failure five years ago in San Francisco and parts of San Mateo resulted in the payment of $12 million in claims by PG&E;, Butler said.

The California Public Utilities Commission also is investigating the power failure. Spokeswoman Terrie Prosper declined to comment on PG&E;’s findings, saying, “Whether their preliminary investigation lays blame on their doorstep or not, we will do our own.”