Equipment failure at a utility station and a subsequent fire pulled the plug on San Francisco on Friday, cutting power to downtown businesses and homes for hours.
An outage that began late in the morning and continued into the afternoon cut power to about 88,000 customers in the busy heart of the city, according to Pacific Gas and Electric spokesman Paul Doherty.
"We deeply apologize for the inconvenience this has caused around the city," Doherty told.
"We know it was an equipment failure. It is premature to speculate on a specific cause," he said, while discussing the cause of the fire.
Traffic lights were out of service and shops plunged into darkness. But many people seemed to take the outage in stride, leaving offices or apartments to socialize on streets where traffic was more subdued than on typical work days.
Some cafes or shops continued to serve customers, with people using cash or mobile payment services such as Square that let credit or debit cards be processed through smartphones or tablets.
