Firefighters keep watch after setting a backfire during the Station Fire in La Crescenta area of Los Angeles, California August 31, 2009. (Xinhua/Reuters Photo) Photo Gallery>>>

    LOS ANGELES, Sept. 3 (Xinhua) -- The wildfire that has wrecked havoc on the Angeles National Forest in Northern Los Angeles was caused by arson, authorities announced on Thursday.

    "After a forensic examination of the point of origin of the Station Fire, arson investigations from the Los Angeles County Sheriff's Department arson/explosives detail, United States Forest Service and Los Angeles County Fire Department have concluded the Station Fire was the result of an act of arson," according to a statement by the Los Angeles Sheriff's Department (LASD).

    A "crime scene" area cordoned off with yellow tape has been established near the fire's suspected point of origin north of La Canada Flintridge in Northern Los Angeles, according to the statement.

    Authorities have launched a homicide investigation. But despite concluding that the fire was arson, fire and sheriff's officials did not immediately say exactly how the fire was started.

    Members of a bomb squad also arrived at the scene but officials declined to say what their role was in the probe. "We believe it is the point of origin," Los Angeles County Fire Capt. Mike McCormick said. "They are doing a finely detailed, serious, serious search and investigation."

    Since its breakout last Wednesday, the Station Fire has claimed the lives of two firefighters, burned 226 square miles (about 362 square kilometers) and destroyed about 140 structures, including 64 homes and three commercial buildings. It has cost more than 27 million dollars to battle.

    An estimated 10,020 homes and 500 commercial buildings remain threatened.

    Mike Dietrich, the Station Fire incident commander, said fire crews made excellent progress battling the blaze on Thursday. He noted, however, that six firefighters had to be hospitalized earlier in the day when they were exposed to some sort of hazardous material while conducting mop-up operations on the northeast corner of the fire.

    But they were not seriously injured and were recovering, Dietrich said.

    Other than the six firefighters who were hospitalized on Thursday, seven other people were injured earlier in the blaze.

    "I want to say that firefighting conditions are still very treacherous out there, with firefighters being exposed to steep terrain, rolling rocks and hazardous materials," Dietrich said.

    He said the heavy smoke looming above the fire grounded many of the water-dropping airplanes and helicopters from battling the fire.

    "But the good news is that the smoke inhibited fire behavior, so the fire was essentially held down by the smoke in the area," he said.

    The weather is expected to remain relatively unchanged for the next several days, Dietrich added.

    The Forest Service said 4,735 firefighters, including 107 hand crews, are deployed in battling the fire, along with 11 air tankers, 12 helitankers, seven helicopters, 433 fire engines and 60 bulldozers.

    The threat to Mount Wilson, home to an historic observatory and communications tower used by the bulk of Southern California television and radio stations, has diminished, according to fire commanders.

Progress being made toward taming Los Angeles wildfire

The Station fire burns on the hills in the Tujunga area of Los Angeles, California September 1, 2009. (Xinhua/Reuters Photo) Photo Gallery>>>

    LOS ANGELES, Sept. 2 (Xinhua) -- Assisted by rising humidity and dipping temperatures, firefighters managed to slow the spread of a wildfire in northern Los Angeles, fire commanders said on Wednesday.

    The Station Fire has grown by another 13,000 acres (5,265 hectares) overnight, but its spread was being contained, said Capt. Mike Dietrich, the Station Fire incident commander. Full story

LA wildfire kills 2 firefighters, traps 5 civilians

    LOS ANGELES, Aug. 31 (Xinhua) -- Two firefighters were killed and five civilians were trapped on Monday as a massive wildfire continued its multi-direction spreading through the Angeles National Forest, authorities said.

    The car the two firefighters were in ran off a mountain road on Sunday after being "overrun by a fast-moving fire," according to a county fire statement. Full story