LOS ANGELES (AP) — Powerful gusts pushed flames from a wildfire through Southern California canyons on Thursday, one of several blazes that burned near homes and forced residents to flee amid elevated fire risk for most of the region that prompted utilities to cut off power to hundreds of thousands.

The biggest blaze began late Wednesday as a house fire in Orange County’s Silverado Canyon, where gusts topped 70 mph (113 kph).

“When crews arrived it was a fully engulfed house and the winds were extremely strong and they pushed flames into the vegetation,” said Colleen Windsor, a spokeswoman for the county’s Fire Authority.

The fire grew to more than 11 square miles (29 square kilometers) and blanketed a wide area with smoke and ash.

Crews struggled in steep terrain amid unpredictable Santa Ana winds that sent flames racing across major roads. Two firefighters were hospitalized after being injured on the fire lines, the Fire Authority said on Twitter without offering additional details.

Evacuations were ordered for several canyons and foothill neighborhoods near the city of Lake Forest and residents of other nearby areas were told to be ready to get out.

It was not immediately known how many people were affected. Some structures were damaged, but it was not immediately clear how many, Windsor said. There was no containment of the fire.

Numerous studies have linked bigger wildfires in America to climate change from the burning of coal, oil, and gas. Scientists have said climate change has made California much drier, meaning trees and other plants are more flammable.

The Bond Fire about 50 miles (80 kilometers) southeast of Los Angeles is burning near the same area of October’s Silverado Fire, which forced tens of thousands of people to evacuate.

Ryan Kayrell fled the October fire with his wife and two young children. But the family stayed at their home in the community of Foothill Ranch on Thursday morning even though it lies in a very smoky mandatory evacuation zone. The family’s bags were packed as they waited to see which way the flames move, Kayrell said,

“A lot of the hillside immediately behind my house is already burned, so we’re hoping that’s a buffer. Which isn’t to say that there’s no danger. The concern is that embers could fly into the neighborhood,” Kayrell said. “If there are fire trucks on our street, we’re going.”

The new blaze broke out as Southern California utilities cut the power to tens of thousands of customers to avoid the threat of wildfires during the notorious Santa Anas.

Red flag warnings of extreme fire danger through Saturday were in place because of low humidity, bone-dry brush and the winds, which sweep down from the interior, the National Weather Service said.

Utilities in the populous region began cutting power Wednesday to customers as a precaution to prevent gusts from blowing tree limbs into electrical equipment or knocking down power lines, which have sparked devastating wildfires in recent years.

Southern California Edison cut power to about 15,000 homes and businesses by late Wednesday night and was considering de-energizing lines serving about 271,000 customers in seven counties throughout the windy period, which could last into Saturday.

It was one of the utility’s largest precautionary blackouts.

San Diego Gas & Electric pulled the plug on about 24,000 customers by Wednesday night with another 73,000 in the crosshairs.

“We recognize losing power is disruptive, and we sincerely thank our customers for their patience and understanding,” the utility said.

A few miles to the north, a blaze near Corona Municipal Airport shut down State Route 71 and had residents getting ready to flee.

Evacuations were ordered when a small wildfire broke out near the rural community of Nuevo in Riverside County, about 50 miles (80 kilometers) to the east.

And to the south, a small blaze in San Diego County threatened about 200 homes and prompted evacuations before firefighters managed to contain 50 percent of it.

California already has experienced its worst-ever year for wildfires. More than 6,500 square miles (16,835 square kilometers) have been scorched, a total larger than the combined area of Connecticut and Rhode Island. At least 31 people have been killed and 10,500 homes and other structures damaged or destroyed.

The latest fire threat comes as much of California plunges deeper into drought. Virtually all of Northern California is in severe or extreme drought while nearly all of Southern California is abnormally dry or worse.