KENSINGTON, Calif.—With no lights, orthodontist Claire Ferrari put on a battery-operated headlamp so she could adjust a young man’s braces Thursday morning at her office near Berkeley during the second day of mass blackouts in California. She had to improvise with the dental chair too, laying the patient upside down, because the chair couldn’t recline completely without power.

Parts of California were expected to remain under a red flag warning through Thursday because of a combination of sustained heavy winds, dry conditions and an abundance of fuel that put the region at high risk of wildfires. Photo: Photo: NOAA

Dr. Ferrari was one of the millions of business owners and residents forced to adapt as PG&E Corp. continued its massive electricity shutdown meant to avert the type of deadly infernos that killed dozens last year and propelled the utility into bankruptcy court. The troubled utility said that about 600,000 customers were still without power Thursday morning and that 126,000 had been restored. PG&E provides gas and electricity to about 16 million people, mainly in Northern California. With multiple people in many households, millions are likely being affected by the power outage.

The utility has said that it could take one to five days to restore power to its customers. Customers were frustrated as they tried to find information on the blackouts because the utility’s website wasn’t working. By Thursday, PG&E had a new, functioning site.

High winds of the sort that some areas of California experienced Thursday and other areas were threatened with can down power lines that, if active, can spark wildfires.

The second phase of the blackout began late Wednesday as PG&E cut power to an additional 234,000 customers, including those in Bay Area cities like San Jose, Oakland and Berkeley. The utility had already cut power to about 513,000 customers across Northern California.

Photos: California Power Outage Continues PG&E continued a widespread electricity shutdown that is meant to avert the type of deadly infernos that killed dozens last year Steven Cohn, an employee at a Garberville, Calif., grocery store, rounded up shopping carts with a flashlight during the power outage. Rachel Bujalski for The Wall Street Journal Leonard Wiggins, right, waited for his propane tank to be filled at a service station in Willits, Calif. Rachel Bujalski for The Wall Street Journal Peter Nelson sat outside his comedy club during the blackout in Eureka, Calif. Ian Lovett/The Wall Street Journal Joe Dell'Ara and Thomas Watson filled gasoline containers for the towing company that employs the two drivers, ahead of expected service calls during power outages in Mendocino County, California. Rachel Bujalski for The Wall Street Journal ‘Not for Sale’ signs we pinned across food at the North Coast Co-Op in Eureka, Calif. Rachel Bujalski for The Wall Street Journal The power has returned to some places like Garberville, Calif. Rachel Bujalski for The Wall Street Journal A sign offered a simple message for utility PG&E at the side of a road in California's Napa Valley on Thursday. josh edelson/Agence France-Presse/Getty Images A vacant gasoline station in Santa Rosa, Calif., after power was shut off on Thursday. josh edelson/Agence France-Presse/Getty Images A food truck in Napa, Calif., on Wednesday night offered a much-needed item: light. David Paul Morris/Bloomberg News Patrons dined by candlelight at Reel and Brand in Sonoma, Calif., Wednesday, during a planned power outage by PG&E. brittany hosea-small/Agence France-Presse/Getty Images A customer shops for groceries at La Tapatia Market during a blackout in Napa, Calif., on Wednesday. David Paul Morris/Bloomberg News Paper products are delivered to a cafe in downtown Sonoma, Calif., on Wednesday. Noah Berger/Associated Press

Meanwhile, Southern California Edison shut off electricity on Thursday to nearly 13,000 customers in parts of Los Angeles, Kern, San Bernardino and Ventura counties due to the possibility that downed power lines could spark wildfires there.


High winds overnight fueled a 40-acre wildfire in Moraga, one of the Bay Area towns hit by the blackout. Homes were evacuated as firefighters battled the blaze, which was mostly contained by Thursday morning. There were no reported deaths or serious injuries.

Cities were grappling with the loss of power overnight and throughout the day Thursday. In Oakland, crews were busy putting up signs to change intersections with traffic lights into four-way stops. In Morgan Hill, a small city south of San Jose, police said they were enforcing a curfew from 7 p.m. to 6:30 a.m. for pedestrians.

“This curfew is for the safety of the community to reduce the opportunity for crime,” the city said on Facebook.

In Kensington, near the orthodontist office, Mairie Raxakoul was trying to keep her inventory of cheeses cool with dry ice at Raxakoul Coffee and Cheese. She tried to rent a generator, but none was available, she said.


“We cannot afford to be closed,” said Ms. Raxakoul.

In Half Moon Bay, Discount Cigarettes and Cigars was one of the handful of the 30 shops and restaurants open in the Strawflower Village shopping center Thursday afternoon. But the shop faces potentially devastating losses because the humidors it needs to keep an estimated $60,000-$70,000 worth of cigars cool and moist had lost power hours earlier, said owner Haron Rahmati. The cigars dried out so quickly that about half the customers who journeyed to the store Thursday morning refused to make a purchase. The cigars, which cost as much as $600 a box, aren’t covered by insurance.

“This thing is killing me,” Mr. Rahmati said.

—Erin Ailworth and Katherine Blunt contributed to this article.


Write to Zusha Elinson at zusha.elinson@wsj.com and Jim Carlton at jim.carlton@wsj.com