While it was man, officials determined, who started the inferno that has threatened Los Angeles since Aug. 26, natural forces are helping fire crews take control of the blaze. Cooler temperatures and higher humidity in the mountainous Angeles National Forest have helped firefighters gain control of 49 percent of the fire by Saturday afternoon. Though smoke still blanketed parts of the area, all of the evacuation orders had been lifted. Over a week and a half, the fire, known as the Station Fire, scorched nearly 242 square miles of the mountains and foothills north of Los Angeles, making it the largest on record in the county. But by Saturday, the San Gabriel Wilderness Area, a rugged, 56 square-mile part of the forest, was the only area where the fire was still burning, according to the U.S. Forest Service, which is leading the fire fight. It destroyed 76 residences and left nine people injured. But it was the deaths of two firefighters last week that prompted the Los Angeles County Sheriff's Department to open a homicide investigation on Friday, after determining the fire was set intentionally. Crews pressed northward toward the San Gabriel wilderness, spraying foam into the heat from the ground, while a water-filled plane circled above. Firefighting crews from around the country were 'confident in achieving success in completing this primary control line by tomorrow morning,' according to a Forest Service update. Four hundred firefighters were using 'coyote tactics': building a controlled fire line to burn off fuel, sleeping next to their handiwork and waking up to start the process over the next day. In all, 5,244 firefighters were involved in the effort. In addition to controlling the fire's western front, officials were also looking forward -- clearing out debris basins and sediment storage areas, in preparation for severe erosion when the rain comes, The Los Angeles Times reported -- and backward, trying to determine who set the fire. KTTV in Los Angeles reported that an accelerant had been found near the suspected origin of the blaze, near Mile Marker 29 of the Angeles Crest Highway. Gov. Arnold Schwarzenegger has offered $100,000 as reward for information leading to the arrest and conviction of an arsonist. The state has already spent $37 million to fight the blaze, according to The Associated Press. Fire Capt. Tedmund Hall and Spc. Arnaldo Quinones were killed when their truck careened off a mountain road on Aug. 30. A service in their honor was scheduled for Sept. 12. The Station Fire had confounded firefighters, whose efforts were hampered by 100-degree heat, rugged terrain and dry brush that had built up over decades without a fire. Officials expected to contain the fire on Sept. 15. 