A forest fire in the southern Sierra Nevada grew to more than 8,100 acres on Wednesday, but a fierce air and ground attack helped slow its advance and put containment at 65 percent, fire officials said.

Fire commanders say aircraft will be important Thursday in keeping the fire from high-risk areas in the region 110 miles north of Los Angeles.

The nearly 13-square-mile fire has destroyed one home and threatens 250 more since breaking out Sunday in the Lower Kern River Canyon southwest of Lake Isabella. Portions of the communities of Bodfish and Havila are evacuated.

Full containment was expected on Sunday.

Light winds aided the firefighting effort Wednesday as bulldozers carved firebreaks and crews set backfires to help stop the fire's spread.

Hundreds of residents were forced to evacuate earlier this week when heavy winds kicked up, pushing the flames to the southeast and closer to homes.

About 200 homes lost electricity because of burned power poles, but crews were hoping to have service restored Thursday.

Gov. Arnold Schwarzenegger has declared a state of emergency in Kern County to free up state resources to battle the blaze. The Federal Emergency Management Agency also authorized the use of federal funds to help fight the blaze.

Authorities have said the fire was human-caused but have not determined whether it was an accident or intentional. Firefighting costs have reached $2.5 million.

In northwest Los Angeles County, firefighters made quick work of a pre-dawn 20-acre brush fire accidentally ignited by a vehicle along Interstate 5.

County fire Inspector Matt Levesque says 200 firefighters, three helicopters, a helitanker and two SuperScooper planes responded to the 5:07 a.m. Thursday fire.