Wildfires blown by fierce desert winds forced hundreds of thousands of people in Southern California to flee, reduced hundreds of homes to ashes, and laid a hellish pattern of luminous orange over the drought-stricken region.
One person was reported killed; at least 16 firefighters were injured.
More than 265,000 people were warned to leave their homes.
"It was nuclear winter. It was like Armageddon. It looked like the end of the world," Mitch Mendler, a San Diego firefighter, said.
In all, more than 600 homes were destroyed, including at least 133 in one mountain resort community. Thousands more homes were threatened across the region.
Firefighters - who lost valuable time trying to persuade stubborn homeowners to evacuate - struggled as winds gusting to 70 mph (112 kph) scattered embers onto dry brush, spawning more fires. California officials pleaded for help from fire departments in other states.
"A lot of people are going to lose their homes today," San Diego Fire Capt. Lisa Blake said earlier.
At least 14 fires were burning, said Patti Roberts, spokeswoman for the Governor's Office of Emergency Services.
Governor Arnold Schwarzenegger declared a state of emergency in the seven affected counties, opening the way for government aid. He also made 1,500 California National Guardsmen available, and San Diego Mayor Jerry Sanders said the troops' main focus would be to prevent looting and help with evacuations.
"Its a tragic time for California," he said.
White House deputy press secretary Scott Stanzel said in an e-mail that President George W. Bush called Schwarzenegger to make sure the state is getting the help it needs.
At least 250,000 people were told to flee in San Diego County alone. "It's probably closer to 300,000," said County Supervisor Ron Roberts.
Among them were hundreds of patients moved by school bus and ambulance from a hospital and nursing homes, many still in their hospital gowns and wheelchairs.
In Orange County, a 1,049-inmate jail was evacuated because of heavy smoke. The prisoners were taken by bus to other lockups.
Actors Mel Gibson, Kelsey Grammer and Victoria Principal were among the celebrities forced to abandon their homes over the weekend, their publicists said.