Firefighters battle a wind driven wildfire in the hills of Canyon Country north of Los Angeles, California, U.S. October 24, 2019.

Pacific Gas and Electric Company is shutting off power for 940,000 homes and businesses in Northern California to prevent more wildfires, which have ravaged parts of the state in the past few days.

The planned power shutoffs would leave as many as 2.7 million people without electricity, in what could be the state's largest planned blackout in history. Gov. Gavin Newsom of California declared a statewide emergency on Sunday because of the fires that are being fueled by high winds.

"We are deploying every resource available, and are coordinating with numerous agencies as we continue to respond to these fires," Newsom said. "It is critical that people in evacuation zones heed the warnings from officials and first responders, and have the local and state resources they need as we fight these fires."

The weekend outage is the second major shutoff by PG&E this month, after the company two weeks ago cut power to nearly 2 million people to avoid fires sparked by its electricity lines. Widespread dry, hot and windy weather is expected to affect the utility's service Saturday evening through Monday.

Los Angeles County and Sonoma County have been under a state of emergency since Friday.

The Kincade Fire that started on Wednesday night in Sonoma County had spread to 30,000 acres and was 10% contained as of Sunday morning. About 180,000 people have been ordered to evacuate.

Sonoma County Sheriff's Office said on Twitter that it was the largest evacuation that "any of us at the Sheriff's Office can remember."

Hundreds of miles south, in Los Angeles County, the Tick Fire has destroyed 4,300 acres, forced about 50,000 people to evacuate and consumed nine homes since Thursday.

The National Weather Service warned that an extreme and potentially historic offshore wind event was expected in mountain regions of Northern and Central California between Saturday night and Monday morning. The strong winds could bring explosive wildfire conditions and make the job of firefighters significantly more difficult and dangerous.

"This wind event is forecast to be the most serious weather situation that Northern and Central California has experienced in recent memory," said Michael Lewis, PG&E's senior vice president of Electric Operations.

Shares of PG&E plunged to $5 on Friday, a 30% decline that could hamper the company's attempt to make its way out of bankruptcy. The stock decline followed reporting that PG&E's transmission lines were active in the area where the Sonoma County fire sparked. The company's stock has declined by almost 90% over the past 12 months.

PG&E's equipment has sparked 19 major fires in 2017 and 2018, and the company was blamed for last year's Camp Fire that destroyed the town of Paradise and killed 86 people.

PG&E said that customers can now expect rolling power outages for another 10 years as it upgrades its electrical systems in response to more extreme weather conditions in California.

The company's preemptive outages have come under severe scrutiny by those who argue that electricity shutoffs threaten lives and local response efforts to fire emergencies, and shift responsibility away from PG&E and onto the public.

But PG&E has defended the outages as critical for the safety of its customers.

"We would only take this decision for one reason – to help reduce catastrophic wildfire risk to our customers and communities," Lewis said. "There is no compromising the safety of our customers, which is our most important responsibility."