About 21,000 San Francisco PG&E customers were still without power Sunday morning after a massive power outage left about a third of the city in the dark on Saturday.

In an update Sunday morning, PG&E said it had restored power to 110,000 customers. Those without power were in the Presidio, Richmond District, Golden Gate Park and small areas within Downtown.

According to the utility company, there was a fire at one of their substations, and it caused "significant and extensive" damage.

"The repairs and safe restoration will be complex," PG&E said. "We have mobilized additional engineers and electricians."

There was no estimated time for when power would be fully restored, PG&E said. 

In Mayor Daniel Lurie's update, he said he would be trying to get more information from PG&E on when power would be restored.

"About 20,000 customers remain without power, primarily in the Richmond and Presidio. I have been in touch with community leaders in those neighborhoods and we're working to bring resources directly to those communities," Lurie said. "We will continue to push PG&E for a firm timeline on full power restoration. We will continue to provide updates later this morning."

Waymo suspends service

The autonomous driving technology company suspended its robotaxi services during the power outage.

"We have temporarily suspended our ride-hailing services given the broad power outage in San Francisco. We are focused on keeping our riders safe and ensuring emergency personnel have the clear access they need to do their work," Waymo said.