Middletown, Calif. — Crews made gains overnight on one of the worst wildfires in California history, mopping up hot spots and strengthening control lines after it and two other blazes in the northern part of the state have combined to kill several people and destroy nearly 1,600 homes.

In the smallest blaze, a body was found outside his burned-out car after flames ignited this weekend in Monterey County, but authorities said they were investigating the man's death as a possible suicide.

The Monterey County coroner planned an autopsy Monday to determine the cause of death. The coroner hasn't released the man's name pending notification of his family.

California Department of Forestry and Fire Protection officials say haven't determined the cause of the fire and whether the man's suicide played a role. The 1,086-acre fire has destroyed 10 homes and was 30 percent contained Monday morning.

In a separate blaze about 100 miles north of San Francisco, damage-assessment teams have counted 1,050 homes destroyed by fire, many of them in the town of Middletown, making it the fourth-worst wildfire in state history based on total structures burned, Cal Fire said.

The Lake County fire, which has killed at least three people and charred 118 square miles, was 70 percent contained Monday. About 3,500 homes were still at risk. A 1991 fire in the Oakland Hills ranks as California's deadliest fire and its worst in the number of structures destroyed, with 2,900.

Meanwhile, crews this weekend counted more homes destroyed by another blaze 200 miles south of San Francisco. The fire, which has killed at least two people and burned 110 square miles in the Sierra Nevada foothills, was more than 70 percent contained. It still was threatening thousands of structures, but all evacuation orders have been lifted.

The fast-moving flames that started Saturday in Monterey County destroyed or damaged 10 homes. A firefighter lost his home while battling the blaze, said Eric Walters, a spokesman for the Cachagua Fire Protection District.

"I was out fighting the fire on the other end, and then my whole place burned down," Bob Eaton, a volunteer firefighter with the Cachagua Fire Protection District, told the Santa Cruz Sentinel. "My parent's house, right below me, it burned down. And my neighbors up on top, their place is burned down."

Eaton said firefighters' quick response wasn't enough to save some of the homes.

"It just went so damn fast," he said of the spread of the fire.