A U.S. Forest Service firefighter sets an intentional backfire to keep flames away from homes in Leona Valley, just west of Palmdale, Calif., and along Lake Elizabeth Road. Brush fire swept over more than 7 square miles, prompted evacuations and burned structures in rural Los Angeles County Thursday as water-dropping helicopters and crews scrambled to get ahead of the blaze. About 1,200 homes in the community of Leona Valley were under mandatory evacuation orders on Thursday evening, Los Angeles County Fire Inspector Matt Levesque said. Firefighters have no idea as to when the fire can be controlled. (AP Photo/Mike Meadows)

Photo by: Mike Meadows

A U.S. Forest Service firefighter sets an intentional backfire to keep flames away from homes in Leona Valley, just west of Palmdale, Calif., and along Lake Elizabeth Road. Brush fire swept over more than 7 square miles, prompted evacuations and burned structures in rural Los Angeles County Thursday as water-dropping helicopters and crews scrambled to get ahead of the blaze. About 1,200 homes in the community of Leona Valley were under mandatory evacuation orders on Thursday evening, Los Angeles County Fire Inspector Matt Levesque said. Firefighters have no idea as to when the fire can be controlled. (AP Photo/Mike Meadows)