Officials say the two biggest wildfires ravaging the Los Angeles area this week have burned at least 10,000 homes, buildings and other structures.

Seven of nine Los Angeles firefighters injured when a truck’s fuel tank exploded have been released from a hospital.

(AP Photo/Mark J. Terrill)LOS ANGELES Police and fire investigators launched a criminal probe Sunday into the cause of an explosion at a hash oil manufacturer in downtown Los Angeles that sent firefighters running for their lives. Mayday mayday mayday! Mayday mayday mayday! another shouted. Things could have been so much worse, said Los Angeles Fire Department Medical Director Dr. Marc Eckstein, who helped treat the injured at Los Angeles County-University of Southern California Medical Center. ___Associated Press writers Michael Blood and Christopher Weber in Los Angeles and Daisy Nguyen in San Francisco contributed to this report.

Mayor Eric Garcetti told reporters Tuesday there is no evidence of arson and the cause of the blaze was accidental. The fire department had done tree and brush clearance in that area as recently as July, in an effort to keep power lines clear. The video was shared on Twitter by Los Angeles Fire Department spokesman Erik Scott. The power lines remained intact, but likely arced and sparked brush. Officials have yet to determine who owns the land where the fire started, the department said.