Much of downtown San Francisco was left without power following a fire at a utility substation. The city's financial district and the popular shopping area near Union Square were affected.
Known for their technological prowess, San Francisco residents were left clamoring for wifi on Friday as the city became paralyzed by a mass power outage.
The blackout broke shortly after 9am local time (1500 UTC) and was triggered after a fire broke out a utility substation. Some 90,000 customers of the Pacific Gas & Electric (PG&E) utility company were affected for several hours across fourteen San Francisco neighborhoods, including the city's technology and financial centers, as well as the popular shopping district near Union Square.
Only by 5pm local time could PG&E confirm that it had restored power to all its customers.
Company spokesman Barry Anderson said the outage was a "case where the equipment failed before we could get to it," adding that something went wrong with a circuit breaker although the utility wasn't yet sure precisely what had happened.
Office workers in the center of the city were seen spilling out on to the sidewalks, wandering the streets for an open café with working power, while major retailers such as Macy's and Louis Vuitton for forced to close shop for the morning.
Meanwhile, the Saint Francis Memorial Hospital in the Nob Hill neighborhood was forced to cancel all non-essential appointments and procedures, a spokeswoman said.
San Francisco International Airport was able to remain operational throughout the day.
Keep calm and enjoy the sunshine
A spokesperson for the US Department of Homeland Security was quick to dispel any fears that the outage was related to a security or terrorism incident.
Those claims were backed up by Joe Weiss, an expert on control system cyber security. "This had nothing to do with cyber," he said. "The real question is how could one substation take out, effectively, San Francisco? What other failures occurred there that didn't isolate this?"
While such an investigation may be pending, in the meantime San Francisco Police Chief William Scott urged residents to savor the sunny spring day. Rather than cross one of the cities bridges to an area with power, he told those affected to "see the city and enjoy the restaurants, enjoy the parks and whatnot."
dm/bw (AP, Reuters)