California building explosion investigated as intentional

LOS ANGELES — An explosion that rocked a Southern California medical building, killing the owner of a day spa and seriously injuring two patrons, is being investigated as a crime after federal officials found remnants of an explosive device inside the spa, officials said Wednesday. The explosion occurred Tuesday in Aliso Viejo, about 50 miles (80.5 kilometres) south of Los Angeles. It blew siding off the walls, exposing insulation and framing and shattering windows at the two-story building.

“At this point, we do not believe this was an accident,’’ said Paul Delacourt, special agent in charge of the FBI’s field office in Los Angeles. “Our working theory is that this explosion was caused by a device.’’

Pieces of the device found at the scene were being sent to the FBI’s laboratory in Quantico, Virginia, to be analyzed, he said.