SANTA BARBARA, California (CNN) -- A wildfire that destroyed more than 200 structures, including several mansions in a community where celebrities own homes, was sparked by a bonfire that its makers apparently thought was extinguished, authorities said.
The wildfire -- one of three that destroyed more than 800 structures in Southern California since last week -- started Thursday, hours after 10 young adults left a private Santa Barbara County estate where they had gathered around a bonfire, Sheriff Bill Brown said.
The 10 apparently thought they had extinguished the bonfire Thursday morning, Brown said.
Brown said it doesn't appear to be a malicious act, but that the case has been turned over to prosecutors to see whether criminal charges should be filed.
In a press release, the sheriff's department said an anonymous tip helped investigators determine the fire's origin.
The 10 "didn't have permission" to be on the Tea Garden Estate, where the bonfire was, county fire Capt. Eli Iskow said.
The so-called Tea Fire burned 1,940 acres and destroyed dozens of structures, including the Montecito home of actor Christopher Lloyd.
"It's amazing, its just gone," Lloyd told ABC's "Good Morning America" on Monday. "Rebuilding would be -- it's too much. You can't rebuild that."
Meanwhile, firefighters in Southern California said Tuesday the Tea Fire was contained, and that they were gaining control of the other two wildfires, all of which have scorched more than 42,000 acres and hundreds of homes and other structures. Watch how families struggle to cope with loss of homes »
The so-called Sayre Fire in Los Angeles County destroyed 519 structures, including nearly 500 mobile homes in the Oakridge Mobile Home Park, located in Los Angeles' Sylmar district.
Residents of the mobile home park on Tuesday were allowed access to their homes and try to salvage belongings. The homes were destroyed Saturday after flames whipped by winds of up to 70 mph swept through. See how flames brought destruction to neighborhoods »
Authorities have said they believe all the park's residents left as the fire approached, and no human remains were found there. Still, 166 residents remain unaccounted for, and officials were attempting to ascertain their whereabouts.
The Sayre Fire, which authorities said was 70 percent contained as of Tuesday, scorched some 11,207 acres. Five firefighters and one civilian sustained minor injuries.
The largest of the three wildfires, the Freeway Complex Fire, was 75 percent contained as of Tuesday, according to the Orange County Fire Department.
The fire has burned through nearly 29,000 acres in Orange, Los Angeles and Riverside counties. Most of the damage was in the Orange County suburbs of Anaheim and Yorba Linda. The fire destroyed some 155 structures and damaged 104, fire officials said. Nine firefighters suffered minor injuries. Nearly 3,700 firefighters remained on scene, battling the flames.
Brian Stanley of Anaheim Hills salvaged a childhood keepsake, a teddy bear he received when his parents moved to the United States from England 45 years ago.
"To see it survive this, that's incredible because it was my mom's before and she survived World War II," he said.
The mobile home fires have prompted California officials to toughen up building codes. Gov. Arnold Schwarzenegger said regulations requiring the use of ignition-resistant materials on single-family homes near fire danger zones should be extended to mobile homes. See views of mobile home park before and after fire »
"We should start thinking about building also the mobile homes with the same retardant materials that we now build in those fire-prone areas, when we build homes. I think that we would have saved probably a lot of those mobile homes," Schwarzenegger said on Sunday.
CNN's Kara Finnstrom and Dawn Tamir contributed to this report.