A significant power outage swept across vast areas of San Francisco on Saturday, leaving approximately 130,000 homes and businesses without electricity. The blackout also caused self-driving vehicles to come to a standstill on city streets.

Pacific Gas and Electric Co. has yet to disclose the exact cause of the outage, which affected about one-third of the utility’s customers in San Francisco. However, fire officials reported via X around 3:15 p.m. that the outage was at least partially due to a fire inside a PG&E substation located at 8th and Mission streets.

The blackout initially affected the city’s northern sections, including the Richmond and Presidio neighborhoods, as well as areas surrounding Golden Gate Park, before expanding further in the afternoon.

As a result, autonomous vehicles halted mid-route, leading to traffic congestion in the impacted zones.

In a snapshot of the city, San Francisco’s skyline was shrouded in fog and darkness on Saturday, December 20, 2025, while traffic moved through the streets. (AP Photo/Jeff Chiu)

The San Francisco Department of Emergency Management advised on X about “significant transit disruptions” occurring throughout the city. Residents were urged to refrain from nonessential travel and to treat intersections with non-functioning traffic lights as four-way stops.

A Waymo vehicle sits idling at an intersection with no operating traffic lights due to power outages, in San Francisco, Saturday, Dec. 20, 2025. (AP Photo/Jeff Chiu)

Waymo temporarily suspended its autonomous ride-hailing service in the wake of the blackout, SFGate reported.

Fox News Digital reached out to Waymo for comment but did not immediately hear back.

A bicyclist drives past headlights from an oncoming vehicle as power outages darken the streets, in San Francisco, Saturday, Dec. 20, 2025. (AP Photo/Jeff Chiu)

PG&E later said that as of 11:30 p.m. Saturday, crews had restored power to about 95,000 customers, with about 35,000 customers remaining without power. The utility company added that crews would continue working through the night.