The investigation of last week's deadly crash North of Sacramento is hitting high gear.
Investigators in Orland are searching for clues in the wreckage of a bus and FedEx truck, which collided last week, killing ten people -- including five high school students on a college tour.
Both drivers had spotless records, not even a moving violation between them.
Blood samples recovered from each driver will examine if there was any intoxication or medical reason which may have inhibited their reflexes.
Investigators are in Los Angeles to interview crash survivors as they try to piece together the moments leading up to the crash and how survivors escaped.