One firefighter has been killed battling huge forest fires in southern California, as lower temperatures and a forecast for light rain bring hope of respite.
The cost of battling the fires could exceed $2bn
Reinforcements are also expected to arrive from the neighbouring states of Arizona and Nevada to help the 13,000 already deployed.
The fire services are struggling with around 10 separate major fires raging across an area stretching from the Mexican city of Ensenada to the Los Angeles suburbs.
One firefighters was killed on Wednesday and two others seriously injured as they battled a blaze near the mountain retreat of Julian in San Diego County.
It was the first death of a firefighter in the current outbreak of wildfires.
The firestorms have now killed at least 20 people, destroyed more than 2,000 homes and scorched at least 246,400 hectares (616,000 acres) of land.
Glenn Wagner, San Diego County chief medical examiner, warned more victims may be found when the flames are doused.
"This fire was so fast," he said. "I'm sure we're going to find folks who simply never had a chance to get out of their houses."
Several of the dead recovered by rescuers perished only yards from their vehicles as flames and choking smoke overcame them.
California Governor Gray Davis has said the cost of battling the fires - said to be the worst in the region for half a century - could exceed $2bn.
With insurance claims estimated to top $1bn, US President George W Bush has declared the affected areas a disaster zone, pledging the federal government will give all possible assistance.
California governor-elect Arnold Schwarzenegger has flown to Washington DC, to ask for further federal funds to help combat the blazes.
On Tuesday, authorities ordered more than 40,000 residents to leave their homes in the popular lakeside resort of Big Bear, 100 miles (160 km) north-east of Los Angeles, as an inferno made its way over a mountain behind the town.
Northern Mexico is also said to be wreathed in smoke.
Authorities say they are concerned for immigrants illegally crossing the border from Mexico into the US who may become trapped by the flames.
Orange smoke is blocking out the sun over Los Angeles and giant plumes can be seen from space.
"You can dream up horror movies, and they wouldn't be this bad," said Gene Zimmerman, supervisor of the hard-hit San Bernardino National Forest.
At least two of the fires are believed to have been the result of
arson and another is said to have been lit as a distress signal by a lost hunter.
Local residents have told BBC News Online how they escaped the flames.
"The fire was right above my house," Daniel Vale from Rancho Cucamonga in San Bernardino County said.
"People were frantically evacuating, the whole sky seemed as if it was on fire.
"The winds were blowing about 70 miles per hour (113kph) and then the power went out as transformers started to explode in the flames."
Erin McLaughlin, a resident of Claremont about 30 miles (48km) east of downtown Los Angeles, told BBC News Online much of her town had been destroyed.
"The north end of our city burned to the ground, and the air has been brown with smoke since last Thursday," she said.
"Our beautiful college campuses are covered in soot and ash and the air is unbreathable, nor can we go anyplace to escape it because the fire is everywhere."