The October 2007 California wildfires were a series of wildfires that began burning across Southern California on October 20. At least 1,500 homes were destroyed and over 500,000 acres (2,000 km², or about 770 mi²) of land burned from Santa Barbara County to the U.S.–Mexico border. Nine people died as a direct result of the fires;[8] 85 others were injured, including at least 61 firefighters. The raging fire was visible from space.[10] California Governor Arnold Schwarzenegger declared a state of emergency in seven California counties where fires were burning. President George W. Bush concurred, and ordered federal aid to supplement state and local response efforts. Over 6,000 firefighters worked to fight the blazes; they were aided by units of the United States Armed Forces, United States National Guard,almost 3,000 prisoners convicted of non-violent crimes, and 60 firefighters from the Mexican cities of Tijuana and Tecate. The fires forced approximately 1,000,000 people to evacuate their homes, the largest evacuation in California’s history. Major contributing factors to the extreme fire conditions were drought in Southern California, hot weather, and the strong Santa Ana winds with gusts reaching 85 mph (140 km/h). California’s “fire season,” which traditionally runs from June to October, has become a year-round threat due to a mixture of perennial drought and the increasing number of homes built in canyons and on hillsides surrounded by brush and forest. The fires had numerous sources. Several were triggered by power lines damaged by the high winds. One fire started when a semi-truck overturned. Another was suspected as having been deliberately caused; the suspect was shot and killed in flight by state authorities. A 10-year-old boy admitted that he accidentally started the Buckweed Fire playing with matches. Causes of the remaining fires remain under investigation. The last fire was fully contained on November 9, 2007, 19 days after the series of fires started.