RENO, Nev. (AP) -- An elderly man discarding fireplace ashes accidentally touched off the brush fire that raged south of Reno, destroying 29 homes and forcing thousands of people to flee the flames, authorities said.The man admitted his role by improperly disposing of the ashes at his home.Investigators already had tracked the origin of the fire to a location in East Lake on the north end of the Washoe Valley, where the man lives about 20 miles south of downtown Reno.\He came forward on his own accord