(CNN) — The Getty Fire that has burned more than 600 acres in Los Angeles and destroyed a dozen homes likely was started by a eucalyptus tree limb that fell onto power lines, sparking and igniting nearby brush, video and a fire department investigation shows.
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 initial flash was caught on the dash cam of a vehicle traveling in the Sepulveda Pass. The video was shared on Twitter by Los Angeles Fire Department spokesman Erik Scott.
Investigators looked at burn patterns and physical evidence as well as taking witness statements to develop their preliminary opinion. 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.