Fierce wildfires continue to rage across Southern California, threatening more than 60,000 homes as night fell on Tuesday (October 23), forcing half a million people to flee in the state's largest evacuation. California's worst fires in four years, driven by hot Santa Ana winds that have not relented for three days, tormented the San Diego area in the south and threatened mountain communities farther north. Some 1,500 homes and other structures had been destroyed by the fires as of Tuesday night and the 500,000 people evacuated in their path was the largest in the U.S. since Hurricane Katrina hit the Gulf Coast in 2005. Most of the destroyed homes were in the San Diego area, where four major wildfires burned unchecked and one person was killed on Sunday (October 21). Four other deaths were reported among the evacuees and more than three dozen people had been injured, including 18 firefighters. Firefighters battled flames that shot more than 100 feet (30 metres) high, as they desperately tried to save homes in the fires' path. As the firestorms raged past nightfall, Governor Arnold Schwarzenegger asked President George W. Bush to upgrade California's wildfires to a "major disaster," which would trigger federal help. Schwarzenegger said 68,000 homes, from cabins to luxury villas, were threatened state-wide and 10,000 men and women were working the fire lines. More than 300,000 acres (120,000 hectares) have been blackened and the state government put economic losses in the hundreds of millions of dollars. Schwarzenegger praised the government response. "One of the things that has happened in these fires is that everyone came together very quickly. The efficiency factor was extremely high. The local, state and federal government has worked together since day one," he said. He also pledged that California would continue to support those affected by the fires well after the event. Bush planned to visit the fire-stricken area on Thursday (October 25). Several more communities in San Diego were evacuated on Tuesday to escape the wind-whipped wildfires descending upon their homes and ranches. Hundreds of others in the nearby rural community of Harmony Grove who were alerted to the danger also had to haul away livestock. Nervous horses, cows, goats, and the occasional llama were loaded into trailers and transported to various ranches and stables in safer locations. Helicopters buzzed overhead surveying the scene of destruction. Meanwhile utility company workers laboured on the ground to repair damaged electric, telephone and cable wires. Fire trucks, tanker planes, and Blackhawk helicopters on loan from the U.S. military were brought in to assist with the emergency effort.