A Northern California wildfire exploded in size early Thursday as dangerously windy weather prompted the state's largest utility to impose electrical blackouts in an effort to prevent fire catastrophes. Authorities ordered all 900 residents of the community of Geyserville to evacuate after the fire in the Sonoma County wine region north of San Francisco grew to more than 15 square miles.

An Associated Press photographer saw three homes destroyed in the Jimtown area.

Flames consume a home as the Kincade Fire tears through the Jimtown community of Sonoma County, Calif., on Thursday, Oct. 24, 2019. Noah Berger / AP

There were no reports of injuries and no immediate information about what caused the fire, but wildfire risk was extremely high as humidity levels plunged and winds gusted up to 70 mph.

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CBS San Francisco reports Cal Fire spokesman Scott McLean described the difficult conditions firefighters were facing early Thursday. "The wind is definitely pushing the fire," he said. "They (the firefighters) definitely have a fight on their hands."

The fire came two years after a series of deadly blazes tore through the same area, killing a total of 44 people.

Mary Ceglarski-Sherwin and her husband, Matt Ceglarski-Sherwin, lost their Santa Rosa rental home during one of those fires and fled the flames again early Thursday when Mary's asthma awakened her around 2:30 a.m. Their power was still on when they grabbed their small dogs, some clothes and emergency kits they acquired during the last fire.

"I told him, 'We gotta go, we gotta go; I can feel it changing,'" Mary Ceglarski-Sherwin told the Santa Rosa Press-Democrat. "By the time we got out there, we could feel the heat and see the smoke.'"

Embers fly across a roadway as the Kincade Fire burns through the Jimtown community of Sonoma County, Calif., on Thursday, Oct. 24, 2019. Noah Berger / AP

The Pacific Gas & Electric Co. utility on Wednesday began rolling blackouts stretching from the Sierra foothills in the northeast to portions of the San Francisco Bay Area in a bid to keep the electrical grid from causing fires due to wind that can send power lines toppling, starting fires.

The blackouts impacted a half-million people - or nearly 180,000 customers - in 15 counties, and PG&E warned that a second round of outages could occur over the weekend when winds were forecast to return.

Hot and dry Santa Ana winds were expected to hit Southern California Thursday and the Southern California Edison utility warned that it might black out about 308,000 customers - perhaps 750,000 people - depending on the forecast.

#kincadefire is moving quickly. This is why we issued evacuation orders. Be safe, Sonoma County. pic.twitter.com/AdhnZGciq6 — Sonoma Sheriff (@sonomasheriff) October 24, 2019

The San Diego Gas & Electric utility warned of power shutoffs to about 24,000 customers.

The utilities have said the precautionary blackouts are designed to keep winds that could gust to 60 mph (97 kph) or more from knocking branches into power lines or toppling them, sparking wildfires.

Electrical equipment was blamed for setting several fires in recent years that killed scores of people and burned thousands of homes.

"We understand the hardship caused by these shutoffs," PG&E CEO Bill Johnson said. "But we also understand the heartbreak and devastation caused by catastrophic wildfires."

The latest outage comes two weeks after PG&E shut down the power for several days to about 2 million people in northern and central California.

Some of the frustration was being taken out on PG&E employees, the company's CEO said.

Johnson said a PG&E employee was the target of what appeared to be a deliberate attack in Glenn County. He said a projectile that may have come from a pellet gun hit the employee's front window. The employee wasn't hurt.

"There is no justification for this sort of violence," Johnson said. "Wherever you see crews they are there to help you."

Sonoma County Supervisor James Gore said PG&E was better this time about getting information to people who would be affected, but he was still astonished by the need to resort to largescale blackouts.

"I am a big believer in shutdowns to prevent fires. But the thing that erodes public trust is when it doesn't make sense," he said. "You say, 'God, I know if we can put a man on the moon ... we can manage a (power) grid.'"

Meanwhile, in Southern California, a wind-driven vegetation fire dubbed the Old Water Fire burned between 50 and 100 acres with zero containment early Thursday, CBS Los Angeles reports. A spokesperson for the San Bernardino National Forest told the station the fire had "extreme potential" for large growth as Santa Ana winds began to pick up. Evacuations were ordered for portions of north San Bernardino.

Power was shut off to thousands of residents across Southern California Thursday morning, with hundreds of thousands more across Southern California warned to be prepared for the possibility of more planned power outages.