Her team will spend a week to 10 days looking at the bridge, talking to the truck driver whose vehicle hit it, and examining maintenance documents and previous accident reports.
The limo was carrying nine women passengers and a male driver when it caught fire late Saturday night on the San Mateo bridge, California Highway Patrol officer Art Montiel told The Associated Press.
McDonald, the driver of a Nissan 200SX, attempted a "dangerous overtaking manoeuvre at more than 100mph" near Bridge Farm, on Somersham Road on the evening of July 27, police said.