SANTA CLARITA, Calif. -- A firefighting army converged Monday on a dangerous wildfire burning in the mountainous northern fringe of metropolitan Los Angeles after it wildly expanded and forced thousands of people from their homes during the weekend.

Nearly 3,000 firefighters were put on the lines after the fire ballooned to more than 51 square miles since Friday, forced expansion of evacuations to 10,000 homes -- an estimated 20,000 people-- and destroyed at least 18 residences.

Incident commander Mike Wakoski called conditions "explosive" with very fast fire movement.

"It's averaged about 10,000 acres a day," he told reporters. "An acre is a football field, so imagine that, 10,000 football fields a day."

Los Angeles County Deputy Fire Chief John Tripp said that 200 more fire engines were brought in Sunday and Monday to help try to douse the fire, adding to the 120 already there.

"We're building this organization up because as you've seen for three days, the fire wants to get up, it wants to run and it wants to go through 10,000 acres and threaten thousands of homes," said Tripp, who estimated that firefighters saved 2,000 homes in the fire's first three days.

Officials also implored people to leave without delay when evacuations are ordered.

County Fire Chief Daryl Osby said firefighters had encountered residents when they arrived in endangered communities, which forced the firefighters to get those people out of their homes to safety instead of concentrating on putting out the fire.

"They felt that they lost additional structures because they had to stop what they were doing to help citizens evacuate," Osby said.

Despite the fire's intensity, there were no injuries Sunday. During the weekend, authorities discovered a man's burned body in the fire zone. The death remained under investigation Monday.

In Santa Clarita, 30 miles northwest of downtown Los Angeles, Juliet Kinikin said Sunday there was panic as the sky became dark with smoke and flames moved closer to her home a day earlier in the Sand Canyon area.

"And then we just focused on what really mattered in the house," she told The Associated Press.

Kinikin grabbed important documents and fled with her husband, two children, two dogs and three birds.

Lois Wash, 87, said she, her daughter and her dog evacuated, but her husband refused.

"My husband's stubborn as a mule, and he wouldn't leave," Wash told KABC-TV. "I don't know if he got out of there or not. There's no way of knowing. I think the last time I looked, it was about 100 yards from us. I don't know if our house is still standing or not. All we can do is pray."

About 300 miles up the coast, crews battled another fire spanning more than 23 square miles that has destroyed 20 homes and two outbuildings and forced evacuations outside the scenic Big Sur region. The fire was threatening about 1,650 mountain homes and burning mostly out of control.

Brock Bradford lives in a historic house in Palo Colorado, one of the evacuated areas, and could see the flames coming down the road as he fled.

"I hope I don't have to rebuild my house," he told the Monterey Herald. "I'm 66."

In Southern California, retardant-dropping planes were grounded for much of Sunday afternoon because of thick smoke, but they resumed drops on the blaze for a few hours before dusk.

Helicopters released retardant around the perimeter of the fire all day and into the night.

The fire destroyed film sets at Sable Ranch in Santa Clarita, which has Old West-style buildings used for movie locations. It also forced a non-profit sanctuary for rescued exotic creatures to evacuate 340 of its more than 400 animals, including Bengal tigers and a mountain lion.

Associated Press photographer Matt Hartman in Santa Clarita and writer Olga R. Rodriguez in San Francisco contributed to this report.

New life, new destruction for Southern California wildfire@
By Christopher Weber@
THE ASSOCIATED PRESS@
   LOS ANGELES -- A wildfire that destroyed 18 homes has surged back to unpredictable life, darkening the skies north of Los Angeles with black smoke and driving thousands from their homes.
   Some evacuees were about to return to their homes Sunday, two days after the fire broke out, when unexpected winds stirred up the blaze.
   "All the experience we've had with fires is out the window," said Los Angeles County Deputy Fire Chief John Tripp, one of many who noted the fires special volatility on Sunday.
   The blaze had burned through at least 51 square miles of brush and destroyed at least 18 homes, but those numbers could well take a leap Monday when better assessment is done at daylight. Winds were expected to dip and temperatures break overnight before a heating trend toward triple-digits comes later Monday. One person has been found dead in the fire zone. His death was under investigation.
   Juliet Kinikin said Sunday there was panic as the sky became dark with smoke and flames moved closer to her home a day earlier in the Sand Canyon area of Los Angeles County.
   "And then we just focused on what really mattered in the house," she told The Associated Press.
   Kinikin grabbed important documents and fled with her husband, two children, two dogs and three birds. They were back at home Sunday, "breathing a big sigh of relief," she said.
   Lois Wash, 87, said she and her daughter and her dog evacuated, but her husband refused.
   "My husband's stubborn as a mule, and he wouldn't leave," Wash told KABC-TV. "I don't know if he got out of there or not. There's no way of knowing. I think the last time I looked it was about 100 yards from us. I don't know if our house is still standing or not. All we can do is pray."
   About 300 miles up the coast, crews were battling another fire spanning more than 17 square miles that destroyed six homes on Sunday and forced evacuations outside the scenic Big Sur region. The fire was threatening about 1,650 mountain homes.
   Brock Bradford lives in a historic house in Palo Colorado, one of the evacuated areas, and could see the flames coming down the road as he evacuated.
   "I hope I don't have to rebuild my house," he told the Monterey Herald. "I'm 66."
   In Southern California, planes had to be grounded for a long stretch of the afternoon because of the thick smoke, but resumed drops on the blaze for a few hours before dusk.
   Helicopters released retardant around the perimeter of the fire all day and would continue into the night.
   The fire destroyed film sets at Sable Ranch in Santa Clarita, which has Old West-style buildings used for movie locations. It also forced a non-profit sanctuary for rescued exotic creatures to evacuate 340 of its more than 400 animals, including Bengal tigers and a mountain lion.
   ------
   Associated Press photographer Matt Hartman in Santa Clarita and writer Olga R. Rodriguez in San Francisco contributed to this report.
 05:28ET 25-07-16