SANTA CRUZ, Calif. (AP) — Sky-darkening wildfires that took at least six lives and forced tens of thousands of people from their homes blazed throughout California on Friday as firefighting resources strained under the vastness of the infernos authorities were trying to control.
Three major complexes encompassing dozens of fires chewed through a combined 780 square miles of forests, canyons and rural areas flanking San Francisco on three sides.
Statewide, nearly 12,000 firefighters are battling blazes that have scorched more than 1,200 square miles in California, said Daniel Berlant, assistant deputy director for the state Department of Forestry and Fire Protection, known as Cal Fire.
Crews from Oregon, Idaho and Arizona have arrived to relieve local firefighters, he said, with engines on their way from as far away as Maryland and New Jersey.
Tens of thousands of homes were threatened by flames that drove through dense and bone-dry trees and brush. Many of the fires were sparked by lightning strikes from brief thunderstorms — nearly 12,000 since last weekend — as a high-pressure area over the West brought a dangerous mix of triple-digit weather and monsoonal moisture pulled from the south.
Some fires doubled in size within 24 hours, fire officials said.
And while some evacuations were lifted in the small city of Vacaville, between San Francisco and Sacramento, other areas expanded their evacuation areas. The University of California, Santa Cruz, was evacuated, and a new fire burning near Yosemite National Park also prompted evacuations.

Santa Cruz itself, a coastal city of 65,000, wasn’t affected. But Mayor Justin Cummings urged residents Thursday evening to be prepared to evacuate by gassing up their vehicles and packing important documents, medicines and other belongings.
“Prepare early so that you are ready to go at a moment’s notice,” Cummings said.
More than 64,000 people have been ordered to evacuate in San Mateo and Santa Cruz counties, which make up part of Silicon Valley and hug the coast south of San Francisco.
With firefighting resources tight, homes in remote, hard-to-get-to places burned unattended. Cal Fire Chief Mark Brunton pleaded with evacuees to quit battling fires on their own, saying that just causes more problems for professionals.
“We had last night three separate rescues that pulled our vital, very few resources away,” he said.
An anxious Rachel Stratman, 35, and her husband, Quentin Lareau, 40, waited for word Friday about their home in the Forest Springs community of Boulder Creek after evacuating earlier this week. She knows one house has burned but has received conflicting information about the rest of the neighborhood.
“It’s so hard to wait and not know,” she said. “I’m still torn if I want people to be going back to the area and videotaping. I know they cause the firefighters distraction, but that’s the only way we know.”

The couple are in a San Jose hotel with medication she needs after undergoing a transplant surgery last month. She collected her mother’s ashes and some clothes while her husband closed windows and readied the home before they evacuated Tuesday.
“I kept looking at things and kept thinking I should grab this or that, but I just told myself I needed to leave. I didn’t bring any official documents and I didn’t bring my house deed or car title. No passport,” she said.