PERRIS (CNS) - A fire swept through an unoccupied doublewide mobile home Wednesday in Perris, causing extensive damage to the structure. The non-injury blaze was reported at 3:55 p.m. in the 400 block of Placentia Avenue, near Indian Avenue, according to the Riverside County Fire Department. Multiple engine crews who encountered flames spreading rapidly inside the doublewide contained the blaze about 4:20 p.m. They were expected to remain at the scene, mopping up, until about 5:30 p.m. The cause of the fire was under investigation.