California authorities were on the hunt Tuesday for two men suspected of starting one of the wildfires raging across the southern part of the state and into neighboring Mexico.

Arson investigators circulated a sketch of one man, who was seen with another man throwing flaming objects from a van in the area of the so-called Old Fire in San Bernardino County.

"Currently we're pursuing two of the fires as possible arson," Chris Parker, the lead arson investigator from the California Department of Forestry (search), told Fox News.

• Photo Essay: Ring of Fire Surrounds Southern California

Parker said profit and the thrill of setting a fire can be among the motives for arson.

"We get a full spectrum of reasons why they set the fires," he said. "Sometimes they're extremely upset. Other times, they have no remorse at all." 

Tens of thousands of people fled mountain communities in San Diego (search) and San Bernardino (search) counties and caused a traffic jam on a narrow mountain highway as frantic residents raced to avoid California's deadliest wildfires in more than a decade.

Frustrated firefighters said there was little they could do to stop the flames, and exhausted crews in San Diego County were pulled back even though two devastating blazes began merging into a super fire near Julian, a mountain town of 3,500 known for its apple crop.

To the north, about 80,000 full-time residents have been evacuated from the San Bernardino mountains since Saturday. Tens of thousands fled on Tuesday alone.

"Just about everything is burning," said William Bagnell, fire chief of the Crest Forest Fire Protection District.

Authorities announced two more deaths in San Bernardino County on Tuesday, bringing the death toll from the fires to 17.

"It's just like a war out here," Capt. Ken Munsey of the San Bernardino Fire Department told Fox News on Tuesday.

Munsey said sleep-deprived firefighting crews were working in harsh conditions.

"We've spent a week straight fighting fires," Munsey said on Fox News. "We sleep when we can. The guys are pretty tired."

Nearly 1,600 homes have been destroyed, and 10,000 firefighters were on the front lines throughout the state.

Gov. Gray Davis estimated the cost at nearly $2 billion.

"This is a total disaster," Davis said. "It reminds me of when I was in Vietnam, communities were burned out."

Since Oct. 21, at least 10 wind-driven wildfires -- many of them arson-caused -- have rampaged through Southern California, demolishing neighborhoods, gutting businesses and blackening more than half a million acres of land from the Mexican border to the Ventura-Los Angeles county line.

Just west of Julian, dozens of fire crews tried to protect homes from flames eating through brush, pine and oak.

A five-member crew pulled up outside a concrete and stucco home and went to work carrying down awnings and using chainsaws to cut away shrubs. As they worked, propane tanks popped in the distance, sending columns of black smoke into a sky already painted orange by flames.

"This is some of the most stressful firefighting I've done," said U.S. Forest Service firefighter Damien Sanchez, a seven-year veteran.

In San Diego County, a blaze of more than 200,000 acres formed a 45-mile front stretching into Scripps Ranch and Julian. The fire was just miles from joining with a 37,000-acre fire near Escondido.

The two fires have destroyed more than 900 homes. If they join up, the flames would cut off escape routes and whip up the wind.

Reinforcements were sent out, but Rich Hawkins, a U.S. Forest Service fire chief, said he needed twice as many firefighters.

"They're so fatigued that despite the fact the fire perimeter might become much larger, we're not willing to let the firefighters continue any further," he said. "They are too fatigued from three days of battle."

Authorities believe the largest, nicknamed the Cedar Fire, was set by a lost hunter trying to signal rescuers. The state forestry department issued Sergio Martinez, 33, a misdemeanor citation for setting an unauthorized fire.

To the north, firefighters had feared they would lose hundreds of homes late Monday and early Tuesday as a fire in the hills between Los Angeles and Ventura counties threatened to push into neighborhoods in the densely populated San Fernando Valley, including one gated community of million-dollar mansions.

But winds subsided enough to let pilots douse the area with water and fire retardant. Backfires and bulldozers were used to clear away the fuel in the flames' path. Reinforcements were sent to help on the ground, and temperatures dropped.

"They saved every one of them," said Bill Peters, a spokesman for the California Forestry Department.

The flames are feeding on millions of dead trees, weakened by drought and killed by a bark beetle infestation. Officials were particularly worried about "crowning," where flames leap from one treetop to another, leaving firefighters on the ground all but powerless to stop them.

"If that occurs, we don't have the capability to put those fires out," U.S. Forest Service spokeswoman Carol Beckley said. "It will be a firestorm."

On the highway near Julian, high walls of flames lit up a mountain ridge along Lake Cuyamaca. The blaze sounded like an explosion as flames tore across the dry brush and trees.

Glenn Wagner, San Diego County chief medical examiner, said he expects the death toll to rise even more as crews begin inspecting the hundreds of charred homes.

"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."

Some victims died within view of San Vicente Lake, a boating and fishing destination in Ramona. "Could you imagine looking out at all that water in San Vicente Lake and still dying in the fire?" Wagner said.

Hawkins, of the Forest Service, said lunches intended for firefighters on Monday were not delivered until Tuesday morning.

"It's like war. This whole fire has been a war so far," Hawkins said. "What the firefighters are facing is a lack of sleep, a lack of food, a lack of diesel fuel in some cases and a lack of logistical support."

Ken Hale, a state Forestry Department division chief who had been on the fire line for 55 hours, said firefighters even drove to nearby towns to gas up their vehicles and buy fast food. But it is all part of the job, he said.

"As soon as I found out people had died, it changes the entire outlook on the fire. It goes from being an adversary, a worthy adversary, to something that's very deadly, a monster," Hale said as he headed for some sleep.

Fox News' William La Jeunesse, Trace Gallagher, Catherine Donaldson-Evans and The Associated Press contributed to this report.