SAN FRANCISCO (AP) — 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.
The fire in the Sonoma County wine region north of San Francisco grew to more than 15 square miles (39 square kilometers) before dawn and authorities ordered evacuations near the small community of Geyserville.
There was no immediate information about what caused the fire, but wildfire risk was extremely high as humidity levels plunged and gusty winds up to 70 mph (113 kph) hit the region.
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 return to the region.
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.
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 Wednesday. "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.
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