The power outage that left up to 130,000 San Francisco residents without electricity Saturday night has been resolved for 90,000 customers. According to the city's main energy provider, power should be restored "overnight" to the remaining 40,000 homes. Here's what we know.

Blackout in San Francisco. Approximately 130,000 residents of the Californian metropolis were plunged into darkness Saturday night due to a massive power outage. According to the latest information, power has been restored to 90,000 customers and should be restored "overnight" to the remaining 40,000 households, announced the city's main electricity provider.

Power was restored to 90,000 homes at 9 p.m. local time on Saturday, Pacific Gas & Electric Company said in a statement.

"The remaining 40,000 customers should have their power restored overnight," the company added, which had previously reported on X that it was working "on an outage in San Francisco affecting approximately 130,000 customers."

According to the city's mayor, Daniel Lurie, the outage was caused by a fire in an electrical substation.

MANY BUSINESSES FORCED TO CLOSE

Much of this West Coast technology hub, home to more than 800,000 people, was plunged into darkness, disrupting public transport, before power began to be restored.

Parts of the city were covered in fog and many businesses were forced to close during the Christmas shopping season, The San Francisco Chronicle reported.

"I know this has been a difficult day," said Daniel Lurie in a video posted on X from the city's emergency operations center. The municipality had previously asked residents to stay home.

"It's progress (the restoration of electricity) but for those of you who don't have electricity, we want to make sure you're safe, check that your neighbors are okay," he added.

Police, firefighters and other municipal officials were dispatched to the scene, asking residents to stay home if possible, Daniel Lurie continued.

The outage rendered many traffic lights inoperative and police officers were deployed at intersections.

The mayor further explained that the autonomous transportation service Waymo has also suspended the operation of its vehicles.

The sharp drop in customer numbers just days before Christmas was "devastating" for businesses, an official at the Black & Gold home goods store told the San Francisco Chronicle.