Wildfires some of largest in Calif. history

SAN FRANCISCO — Lightning-sparked wildfires in Northern California exploded in size Friday to become some of the largest in state history, forcing thousands to flee and destroying hundreds of homes and other structures as reinforcements began arriving to help weary firefighters.

More than 12,000 firefighters aided by helicopters and air tankers are battling wildfires throughout California. Three groups of fires, called complexes, burning north, east and south of San Francisco have together scorched 780 square miles, destroyed more than 500 structures and killed five people. More than 140,000 people are under evacuation orders.

Fire crews with help from “copious amounts of fixed-wing aircraft” were working Friday to stop a large blaze from reaching communities in the West Dry Creek Valley of Sonoma County, he said.

The blazes, coming during a heat wave that has seen temperatures top 100 degrees, are taxing the state’s firefighting capacity but assistance from throughout the country was beginning to arrive, with 10 states sending fire crews, engines and aircraft to help, Gov. Gavin Newsom said.