Firefighters helped by a decrease in winds contained a 3,200-acre fire Saturday that destroyed or damaged 40 homes, while arson investigators searched for two men seen just before the blaze broke out.

The massive fire, which began early Friday in the northwestern San Fernando Valley community of Porter Ranch, was contained by 2:20 p.m. Saturday in the remote Limekiln Canyon area of the Santa Susana Mountains.Some of the 350 firefighters who worked nearly 34 hours to surround the blaze were to remain in the area overnight in case hot embers flared into flame, a county Fire Department dispatcher said. At the fire's peak, more than 1,400 firefighters battled the fire.

Los Angeles Fire Department spokesman Ed Reed said a slackening in strong winds allowed firefighters to gain the upper hand.

"The weather has made a difference," Reed said. "Everything is dependent on the Santa Ana wind conditions."

It was the third fire in two days to hit the Los Angeles area. The other fires, in Baldwin Park and in La Verne, destroyed 21 homes and damaged more than 20 others, with losses estimated at $10.5 million.

The Porter Ranch fire caused $4.3 million in damage, destroyed 15 homes and scorched another 25, Fire Department spokesman Gil Espinoza said.

The cause of the fire remained under investigation, but officials said they had not ruled out the possibility it was caused by downed power lines.

The National Weather Service reported winds had diminished to 20 mph or less Saturday morning. On Friday, near-hurricane force winds gusting to 80 mph pushed the fire into Porter Ranch, forcing 8,000 people to flee.

Fifty firefighters and two residents suffered minor injuries. All were treated for ashes in their eyes or smoke inhalation and released.

As a result of the fires, Gov. George Deukmejian declared a state of emergency in Los Angeles County.