Utility officials increased security at power stations around San Francisco on Friday after FBI investigators said someone intentionally cut power to the city's downtown.
"It was a deliberate act," said FBI spokesman George Grotz. "It was not an accident, and it was not a computer intrusion."Grotz said there was no sign of forced entry into the locked city substation, and agents are looking at records of about 75 employees who had access to the building. Sabotage of an electrical facility is a federal offense.
The switches in the substation were toggled in such a way as to maximize the power outage about 6:15 a.m. Thursday, blacking out electricity to 126,000 customers - about 250,000 people - in a five-mile, mid-city stretch from the Marina to the Sunset districts for 90 minutes or more. The saboteur had cut power coming into and out of the station, Grotz said.