MALIBU, California (CNN) -- A campfire set by people "partying" in the woods may have started a huge wildfire that destroyed dozens of homes near Malibu, California, on Saturday.
Two fire investigators told CNN on Sunday the blaze may have originated at a campfire set at the end of a dirt road, where investigators have determined the 4,720-acre Corral Canyon fire began.
The investigators, speaking on condition of anonymity because the investigation is ongoing, said they hope the people will come forward.
The Los Angeles County Fire Department said the Corral Canyon fire was 40 percent contained as of Sunday afternoon. The Malibu city Web site said officials expect to have the fire fully contained by Tuesday. Watch what arson investigators have learned »
"Given the weather conditions, the wind subsiding ... the amount of fuel that has been consumed in there ... the number of personnel that we have here ... those are all reasons for optimism," Los Angeles County Fire Chief Michael Freeman told reporters Saturday night.
The wildfire began early Saturday and, fueled by dry Santa Ana winds and low humidity, grew quickly, forcing thousands to evacuate. Fire-friendly weather conditions hindered initial efforts to battle the blaze, which consumed dozens of homes in Los Angeles County. Check out where the fire is located »
Los Angeles County Fire inspector Sam Padilla said more homes were threatened, and the number of burned structures -- which stood Saturday at about 50 -- was expected to increase.
Of the 1,700 firefighters battling the fire, a handful received minor injuries, fire officials said. One suffered moderate facial burns, department spokesmen said.
Sia Hodjatie, who lives near Corral Canyon, told CNN Saturday that his older son had called to inform him he may have lost his home.
"I woke up around 3:45 [6:45 a.m. ET] and I smelled the smoke, and I woke up my wife. I said, 'Ursula, get up, there is a fire.' She says, 'I don't see it.' I said, 'But I smell it.' "
Hodjatie said he and his family fled their house about an hour later. "My older son was saying, he said, 'Dad, if we had left 30 or 40 seconds later, we would have been baked here.'"
Red Hot Chili Peppers bassist Flea, whose real name is Michael Balzary, told the Los Angeles Times by text message that his home had "burned to a crisp." See photos of fire's devastation »
Gov. Arnold Schwarzenegger reactivated a state of emergency he declared for last month's devastating California wildfires, pledging he would make quickly available resources to affected Californians.
"No time is wasted in providing any needed resources to fight these fires or help those Californians who have been impacted," he said in a statement.
Operations centers run by the Office of Emergency Services in Los Alamitos and Sacramento were prepared to meet requests for assistance from Los Angeles County, the governor said.
Mandatory evacuations remained in effect Sunday for the area bordered by Corral Canyon to the east, Kanan to the west, Mulholland to the north and Pacific Coast Highway to the south. The Red Cross set up evacuation shelters at Agoura High School and Channel Islands High School, Red Cross spokesman Nick Samaniego said.
Despite thousands of evacuees, only a handful of people arrived by mid-day Saturday at Agoura, he said. "It's a good sign, it shows that people have other resources," he said.
Many residents and officials Saturday were plagued by an unpleasant sense of deja vu.
"I could hear the wind, then I heard the noise of a helicopter, and I thought, 'That can't be good,' " Malibu Mayor Jeff Jennings said Saturday.
Last month's fires charred more than 508,000 acres in several counties, and forced 1 million people from their homes.
However, Jennings remained optimistic. It's "certainly not as bad as it could have been," Jennings said. He urged residents to "listen to the radio; stay alert; stay vigilant." E-mail to a friend
CNN's Ted Rowlands contributed to this report.