Oct. 24 (UPI) -- A rapidly spreading wildfire doubled in size in Northern California on Thursday, causing officials to issue mandatory evacuation orders.
Dubbed the Kincade Fire, the blaze erupted Wednesday night near the Geysers geothermal plant in Sonoma County. It grew to more than 16,000 acres by Thursday night with 5 percent containment, Cal Fire said.
Cal Fire Incident Commander Mike Parkes said the fire destroyed an unknown number of structures and it was unclear how many of those were homes.
Parkes added that authorities expect the fire to continue growing after it burned 5,000 acres 3 hours after forming.
Evacuation orders were in place for several areas in Sonoma County, including Healdsburg and Geyserville, the Sonoma County sheriff's office said in an advisory, describing the severity of the situation as "extreme" as there is "extraordinary threat to life or property."
"If you feel unsafe, evacuate," the sheriff's office said.
Sen. Mike McGuire, D-Calif., warned residents to follow all evacuation notices.
"This fire is moving fast, please pay attention to evacuation orders. Firefighters will be working hard through the night," he said on Twitter.
The National Weather Service said it recorded wind gusts of 76 mph near the fire's location. North Bay, East Bay Hills and Santa Cruz Mountains were also under a red-flag warning for critical fire weather through Thursday afternoon due to strong winds and "very low humidity," the NWS said.
The NWS also predicted smoke to spread to the Bay Area between 10 a.m. and 11 a.m. Friday morning.
The fire erupted as Pacific Gas & Electronic cut power to some 179,000 accounts in 17 counties, including 27,830 customers in Sonoma County, to prevent wildfires caused by dry, windy conditions.
As of Thursday evening, 1250,000 customers had their power restored with 56,000 still out of service, "and that number is dropping fast," said Mark Quinlan, deputy incident commander with the utility.
PG&E CEO Bill Johnson said Thursday in a press conference that they filed an Electric Incident Report with the California Public Utilities Commission stating a transmission line near where the Kincade Fire erupted experienced issues Wednesday night but it is unknown if that was the source of the fire.
He said they became aware of the issue at 9:20 p.m. and a field worker found a broken jumper on a transmission tower, which Cal Fire had tapped off and was investigating.
"Filing the EIR does not tell us where the fire started," Johson said. "Thet fact that we filed it or that Cal Fire is investigating does not actually tell us what caused the fire or where it started."
Though Sonoma County was experiencing a shutdown, the transmission tower was live as PG&E didn't forecast wind speeds that would require it to be de-energized, he said.
"Still, at this point, we don't know exactly what happened," he said.
Earlier, PG&E spokeswoman Karly Hernandez said the fire is burning near the shut-off footprint and "we are working to gather additional information."
Thursday, a second wildfire, named Tick Fire, ignited in Canyon Country and has been spreading through northern Los Angeles County, Cal Fire said.
Los Angeles County Fire Department, the lead agency battling the Tick Fire, said mandatory evacuation orders were in place for residents north and south of 14 Freeway.
The fire, named after the road it ignited near, had grown to 3,950 acres and was only 5 percent contained by Thursday night, the L.A. County Fire Department said.
"Approximately 500 firefighters are currently on-site with additional resources responding from all over the state," the department said in an evening update. "Firefighters will maintain a tactical patrol throughout the evening, protecting structures and looking for opportunities to build containment lines."
Some 40,000 to 50,000 people were impacted by the evacuation orders, said Kathryn Barger, 5th District supervisor for the County of Los Angeles.
In a press conference, Barger said Tick Fire began around 1:42 p.m. and at least six homes had been burned, though that number may rise.
As winds pick up, the focus now is to stop the fire's forward progress and get perimeter control, she said, adding red-flag weather warnings will be in effect until 10 p.m. Friday.