A wildfire raging in a long stretch of the heavily populated Los Angeles foothills threatened 10,000 homes today and marched toward communities on the other side of the mountains, according to Reuters. The heat-driven fire nearly doubled in size overnight and has now burned burned 35,000 acres (14,000 hectares) of bone-dry brush in the mountains above five towns, a 10-mile stretch from La Crescenta to Pasadena, the California Fire Department said. Some 10,000 homes are under evacuation orders and 500 commercial buildings are in danger, as is Mount Wilson, the nexus for key telecommunications facilities, including TV and radio transmission towers, the U.S. Forest Service said. The fire that started on Wednesday above the exclusive community of La Canada Flintridge is only 5 percent contained but firefighters may benefit on Sunday from slightly cooler temperatures, just below 100 degrees Fahrenheit (37 Celsius). The cause of the fire is being investigated. Dense smoke filled the skies over the foothills and prompted authorities to issue health warnings for the Los Angeles basin. The flames appeared to wane on Saturday evening in the area near NASA's Jet Propulsion Laboratory but raged at the other end and moved through the mountains toward the inland community of Acton, where evacuations were ordered on Sunday. The saving grace in this fire has been the absence of high winds but much of the brush in the area has not burned in 60 years and humidity is below 10 percent. Three remote homes have been lost to the flames and three people have been injured. Nearly 2,000 firefighters are on the ground but it is the aerial assault of water and retardant that has best kept the fire from moving into homes, many of them worth millions of dollars. California Governor Arnold Schwarzenegger was scheduled to visit the so-called Station Fire on Sunday morning, the worst conflagration in the Los Angeles area since a spate of fires destroyed hundreds of homes in November 2008. He declared a state of emergency in Los Angeles County last week in response to four fires in the area.