At least 18 homes have burned in a wildfire that exploded to 51 square miles in dry hills and canyons, sending smoke and ash over a widespread part of Southern California and forcing a new round of mandatory evacuations.

Updated Story: Firefighters Battle Flames Through Night in Raging Santa Clarita Blaze

The fire was only 10 percent contained as of 11 p.m. Sunday evening, the third day the blaze had continued to rage.

Authorities said the burned body of a man was found Saturday inside a scorched car in a neighborhood swept by the Sand Fire flames near Santa Clarita, just north of Los Angeles. There was no evidence the death was crime-related, the Los Angeles County Sheriff's Department said Sunday as the investigation continued.

Eighteen homes have burned in Bear Divide, Little Tujunga and Sand Canyon, authorities said Sunday morning after the fire doubled in size since Saturday night. Shifting winds fanned the flames, which raced through neighborhoods late Saturday.

Tim Gieser, who lived in one of the evacuated areas for six years, came back to find "everything gone."

"It's a lot of these people's life savings," said Gieser. "It's a nice serene place to live. There's nothing you can do now. It's all gone."

The fire grew to more than 33,000 acres Sunday evening after firefighters faced another day of hot and dry weather. Firefighters have been trying to battle the fire up and down ridgelines since Friday on the edge of Santa Clarita and the Angeles National Forest.

"Things got in alignment yesterday and that fire came through like a freight train," said Deputy Fire Chief John Tripp, of the Los Angeles County Fire Department.

The area where the body was found was among those ordered evacuated as the fire raged through brush withered by days of 100-degree temperatures as Southern California sweltered through a heat wave. After flames driven by gusty winds swept through an evacuated neighborhood, firefighters reported that some buildings had been engulfed, but it was not immediately clear whether they were homes, outbuildings or garages, said Nathan Judy, a spokesman for the U.S. Fire Service.

The area was still unsafe, he said late Saturday night.

"You've still got hot spots in that area, a lot of smoldering stuff," and trees that might fall because their roots had burned, Judy said.

Areas downwind from the fire are of greatest concern Sunday. Mandatory evacuations were ordered early Sunday afternoon for parts of Acton on Agua Dulce Canyon road north to the 14 Freeway, Crown Valley Road north to the 14 Freeway and all of Soledad Canyon.

By 5:30 p.m., fire officials urged residents who hadn't evacuated to gather belongings and leave after the blaze jumped to Placerita Canyon about 1/4 mile west of Sand Canyon heading in a northern direction, the Los Angeles County Fire Department said.

Residents living in the following areas were under mandatory evacuation orders:

East of the 14 Freeway from Golden Valley Road to Sand Canyon

East side of Via Princessa from Lost Canyon to the end of Via Princesa

All streets east of Lost Canyon Road from Via Princessa to Santa Clara River and all streets east of that area

Agua Dulce Road to the west

Soledad Canyon Road to the south

Acton Camp to the east

Sierra Highway and Shady Lane to Sierra Highway at the 14 Freeway

Escondido at the 14 Freeway to Sierra Highway at the 14 Freeway

Near Sierra Highway at Shady Lane to Sierra Highway at the 14 Freeway

Placerita Canyon about 1/4 mile west of Sand Canyon

Bengal tigers and a mountain lion were among several hundred animals evacuated Saturday as flames partially ringed the Wildlife Waystation, a nonprofit sanctuary for rescued exotic creatures in Sylmar. Volunteers showed up with trucks and trailers to help with the rescue. Later in the day, firefighters managed to beat back the threat.

#SandFire smoke has drifted into the Mojave Desert & #Vegas areas, reducing visibility and air quality #VegasWeather pic.twitter.com/O2Z7pvQM6U — NWS Las Vegas (@NWSVegas) July 24, 2016

More than 200 horses along with goats, rabbits and other animals also were removed from fire areas.

After the 14 Freeway was shut down in both directions for hours Sunday, it was reopened between the 5 Freeway and Soledad Canyon Road.

Fire 'Doing What It Wants'

More than 1,600 firefighters and water-dropping helicopters battled the flames overnight on several fronts.

"It's not a one-direction type of fire," Judy said. "It's going in different directions depending on which way the wind is blowing. It's doing what it wants."

Despite firefighters' efforts, the blaze destroyed sets at Sable Ranch in Santa Clarita, which has Old West-style buildings used for movie locations.

Smoke and ash from the fire cast a pall over neighboring Los Angeles. Air quality officials advised people with respiratory problems to stay indoors.

Sunday's forecast called for low humidity with afternoon and evening winds gusting to 25 mph or more that could once again fan the fires' explosive growth.

Five years of drought and a lack of significant rain from the winter El Nino has made Southern California ripe for what could be one of the worst wildfire seasons on record. An El Nino weather pattern brought near-normal snowfall to parts of California last winter, but most of the precipitation stayed to the north of Southern California, leaving the region with dry brush to fuel fire growth.

"These are not normal times," said Los Angeles County Fire Chief Daryl Osby. "When we say evacuate, that means evacuate."

Up the coast, California Department of Forestry and Fire Protection firefighters battled the blaze in rugged mountains north of Big Sur. The fire 5 miles south of Garrapata State Park posed a threat to about 1,000 homes, burning down 6, and the community of Palo Colorado was ordered evacuated, Cal Fire said.