SAN DIEGO, Oct 23 (Reuters) - Wildfires stoked by fierce winds burned unchecked across Southern California for a third day on Tuesday with 300,000 people in San Diego alone evacuated as flames destroyed or threatened homes from humble forest cabins to luxury villas.
     San Diego Mayor Jerry Sanders told people to "stay at home, stay off the freeways" so fire crews and evacuees could keep moving as the winds changed course. He said about 1,000 homes in San Diego County had been destroyed.
     "We are in for another very dangerous day today. We may be forced to do very quick and immediate evacuations," said Ron Lane, head of San Diego County office of emergency services.
     "We no doubt are going to be issuing additional evacuation notices today," he added.
     Officials said people were cooperating and evacuating quickly, resulting in minimal loss of life, as they remembered the last major fire in 2003 when 15 people died and 5,000 buildings were destroyed.
     "We've been through this before," said Sonya Johnson, 43, who evacuated with her husband and young son and set up camp in the Qualcomm sports stadium.
     "I am sitting here thinking about the things I didn't take, like pictures and our will," she added.
     At least 17 fires, whipped by hot, dry Santa Ana winds gusting to 70 miles per hour (113 kph) have swept the drought-stricken region unchecked over the past two days from Santa Barbara to the Mexican border 230 miles (370 km) to the south.
     Just one person has died, in a San Diego fire on Sunday, and some three dozen have been injured.
     Two new fires erupted overnight in both Los Angeles and San Diego counties and burned quickly. But in the celebrity enclave of Malibu, north of Los Angeles, where the first fire raged early Sunday, there was no active burning and 500 of the 1,400 firefighters were dispatched to other areas.
        President George W. Bush early on Tuesday declared an emergency in the state and authorized the Federal Emergency Management Agency to coordinate disaster relief in the seven counties stricken by wildfires.
     Some 300,000 acres (120,000 hectares) have burned, an area about twice the size of Chicago, stretching fire crews and state emergency services. But federal authorities said the emergency response was well under control.
     High wind warnings remained in effect for most of the region until Wednesday afternoon.

HUMANS, HORSES, PETS

Gov. Arnold SChwarzenegger summoned aid from 1,500 National Guard troops, including 200 from the Mexican border, to help with firefighting, evacuations and crowd control.
     Neighboring states, including Nevada and Arizona, rushed in crews and equipment.
     Tens of thousands of evacuees in San Diego, including senior citizens from nursing homes, went to the Qualcomm stadium, where the National Football League's San Diego Chargers play, or to the Del Mar Fairgrounds, famed for its horse racing track. Thousands of horses and pets were also accommodated.
     Evacuees at Qualcomm said the operation was well organized and clean, a sharp contrast to the chaos at New Orleans' Superdome, which was used as a refuge after Hurricane Katrina flooded the city in 2005.
    But the San Diego residents were anxious to return home and worried about what they left behind.
    "You just get tired, tired of waiting," said Brad Donaldson, 53, who evacuated to Qualcomm with his wife on Monday.
     In addition to mandatory evacuations through much of the area north of the city, voluntary evacuations were announced for South San Diego near the Mexican border.
     The Marine base at Camp Pendleton, one of the largest in the United States, was on alert for possible evacuation of its 60,000 people, including families.
     The firestorms closed major highways, schools and businesses and plumes of thick black smoke drifted across much of Southern California, blotting out the sun.
     The economic costs have yet to be tallied in wealthy San Diego, home to big communications and biotechnology companies as well as a large tourism industry.
     And despite high real estate values in the area, with an average home cost of $500,000, big U.S. insurers were not expected to see major losses from the wildfires, analysts said.

(Additional reporting by Marty Graham in San Diego)