PARADISE, Calif. — Firefighters made some progress overnight to establish control of the Camp Fire in Butte County, which is already the most destructive wildfire in California history.

The amount of acreage burned increased to 100,000 acres but containment jumped from 5 percent to 20 percent. With 6,713 structures burned, including 6,453 homes and much of the town of Paradise, it supplanted the Tubbs Fire in wine country last year that burned 5,636 structures as the most destructive.

Now firefighters are concerned about protecting the city of Oroville.

Nine fatalities have been confirmed, including five who burned in cars while trying to escape the fast-moving flames.

The fire started Thursday at Camp Creek Road in the Feather River Canyon near Pulga. Investigators are looking at PG&E power lines as a possible cause of the fire. The blaze spread into Concow and then Paradise in a matter of hours, overrunning the town.

Three firefighters have been injured, and 3,223 are fighting the blaze. In addition, there are 23 helicopters, 67 bulldozers and 440 engines assigned to the fire.

Strong northeast winds are expected to return Saturday evening, which has firefighters concerned. Despite cold overnight temperatures, the high winds and low humidity make for dangerous conditions.

The most active part of the fire is in the Magalia and Paradise Pines area. Cal Fire reporters that fire lines are holding south of Highway 32 near Chico.

It is also burning toward Big Bend and Berry Creek. Cal Fire said the forecasted northeast winds have them watching the city of Oroville. Cal Fire said the wind "has the potential to drive fire across Lake Oroville threatening the city of Oroville."

Highway 70 is closed between Highway 149 near Oroville and Highway 89 near Greenville.

An evacuation warning was also issued for East-bound Highway 162, Oro Quincy Highway, at Canyon Creek Bridge east to Mountain House Road. They include the communities of Berry Creek, Brush Creek, Mountain House and Bloomer Hill. Winds are expected to increase, which could escalate the warning to an evacuation order.