• About 130,000 people affected by a power outage in San Francisco Saturday

• Disruption hits shops and public transport during busy holiday shopping

San Francisco, US, experienced a widespread power outage Saturday, affecting about 130,000 people at the peak of the crisis, before services gradually resumed, according to the supplying company.

The company said in a statement on X that power had been restored to around 90,000 homes by 9 p.m., with service for the remaining customers expected to return later that night.

The outage plunged large areas into darkness, including the tech hub on the West Coast, home to more than 800,000 people, causing public transport disruptions and the failure of many traffic signals during a busy pre-Christmas shopping period.

San Francisco Mayor Daniel Lowery said in a video from the city’s emergency operations center that the day had been "difficult," urging residents to be cautious and check on neighbors.

He confirmed that police, fire, and other relevant teams were deployed across the city, advising residents to stay home if possible.

He added that the failure of many traffic lights required intervention by traffic police to manage movement.

He pointed out that a fire at a substation was the cause of the outage.

A local newspaper reported that fog covered parts of the city, forcing many shops to close at the peak of the shopping season, leaving usually crowded commercial areas looking nearly empty.