The latest wildfire to scorch Southern California advanced on thousands of homes Wednesday, ravaging several structures as it expanded to at least 25,000 acres while feeding on drought-stricken vegetation.

Flames continued to climb the flanks of the San Gabriel Mountains in San Bernardino County toward the town of Wrightwood, where authorities said that only half of the community's 4,500 residents had complied with evacuation orders.

"This is not the time to mess around," said Battalion Chief Mark Peebles of the San Bernardino County Fire Department. "If you are asked to evacuate, please evacuate."

Officials estimated that more than 34,000 homes and some 82,000 people were under evacuation warnings. No deaths were reported, but cadaver dogs were searching the ruins for anyone who was overrun by the flames.

Authorities did not have an exact number of homes destroyed in the first hours of the explosive wildfire, but warned communities of bad news ahead.

"There will be a lot of families that come home to nothing," San Bernardino County Fire Chief Mark Hartwig said after a flight over the area Wednesday morning that he described as "devastating."

"It hit hard. It hit fast. It hit with an intensity that we hadn't seen before," he said.

The cause of the fire wasn't immediately known.

Five years of drought have turned the state's wildlands into a tinder box, with eight fires currently burning from Shasta County in the far north to Camp Pendleton just north of San Diego.

"In my 40 years of fighting fire, I've never seen fire behavior so extreme," Incident Commander Mike Wakoski said.

Residents like Vi Delgado and her daughter April Christy, who had been through a major brushfire years before, said they had never seen anything like it either.

"No joke, we were literally being chased by the fire," a tearful April Christy said in a voice choked with emotion as she and her mother sat in their minivan in an evacuation center parking lot in Fontana.

They did not go inside because their dogs, three Chihuahuas and a mixed-breed mutt, were not allowed.

"You've got flames on the side of you. You've got flames behind you," Christy said, describing a harrowing race down a mountain road. She was led by a sheriff's patrol car in front while a California Highway Patrol vehicle trailed behind and a truck filled with firefighters battled flames alongside her.

She and her mother, onsite caretakers at the Angels and Paws animal rescue shelter in Devore Heights, said it was only moments after they smelled smoke that flames exploded all around them.

They grabbed their pets and tried to rescue nine other shelter dogs and three cats, but a sheriff's deputy told them there was no time.

"You won't make it. Save yourself. Take your truck and leave," Delgado said the deputy shouted at her, adding that he and others would try to rescue the animals. She learned later that authorities did save the animals, but officials could not tell her if her home survived.

Less than 24 hours after the blaze began 60 miles east of Los Angeles, the fire command assembled a fleet of 10 air tankers, 15 helicopters and an army of 1,300 firefighters, many of them just off the lines of a wildfire that burned for 10 days just to the east. 

At a dawn briefing, half the firefighters raised their hands when an official asked how many had just come from an earlier blaze in Northern California, part of a siege of infernos up and down the state this year.

The fire erupted late Tuesday morning in Cajon Pass, a critical highway and rail corridor through mountain ranges that separate Southern California's major population centers from the Mojave Desert and Las Vegas to the north.

Gov. Jerry Brown declared a state of emergency in the area within hours of the fire breaking out, a move that more often comes after a blaze has done several days of destruction.

Six firefighters were briefly trapped by flames at a home where the occupants had refused to leave, forcing the crew to protect the house, fire officials said.

Countless big rigs were still parked on both sides of the pass as of Wednesday, waiting for Interstate 15 and a web of other roads to reopen. Alternate routes involved significant detours. The pass is a major route for travel from the Los Angeles region to Las Vegas and also carries significant daily commuter traffic for high desert residents.

The speed of the fire's spread astonished those in its path.

"This moved so fast," said Darren Dalton, 51, who along with his wife and son had to get out of his house in Wrightwood. "It went from 'Have you heard there's a fire?' to 'mandatory evacuation' before you could take it all in. This is a tight little community up here. Always in rally mode. Suddenly it's a ghost town."

Hundreds of cars packed with belongings and animals left the town. The air for miles around the blaze was filled with smoke. The sound of explosions — possibly from ammunition stored in homes — could be heard in the distance.

The fast-moving fire destroyed an iconic pit stop that has served locals, Historic Route 66 and interstate travelers since 1952.

The historic Summit Inn restaurant at the top of the pass went up in flames on Tuesday, Fox 11 reported.

The employees of the iconic restaurant, which has served famous celebrities such as Elvis Presley, Pierce Brosnan, and Clint Eastwood, were told to evacuate at around 3:00 p.m. on Tuesday. In less than five hours, the restaurant was gone, according to Fox 11.

Shannon Anderson of Blue Mountain Farms horse ranch in Phelan had to evacuate 40 horses as the fire approached. "It's raining ash," Anderson said, breathing hard.

The fire erupted in a landscape ready to burn after years of drought. The weather at the time was hot, dry and windy — conditions not expected to begin easing until late Thursday or Friday.

Devouring ranchlands, the blaze surged west to the Los Angeles County line and north to the Mojave Desert.

Eric Sherwin of the San Bernardino County Fire Department confirmed Tuesday night that the flames had burned at least a dozen buildings, some of them homes.

"I'm looking up here and I'm seeing buses [burn]. I'm seeing outbuildings. I'm seeing houses," he said.

The blaze was among several large fires burning up and down California, from Shasta County in the far north to Camp Pendleton Marine base in San Diego County. It came after several steady weeks of major fires around the state, even though the full force of the traditional fire season has yet to arrive.

The Associated Press contributed to this report.

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