Pima County Sheriff's deputies are investigating body parts found along train tracks in Vail.
According to deputy Cody Gress, a conductor on an Amtrak train heading westbound near Colossal Cave Road hit the brakes when he saw what he thought was a pig on the railway.
The train came to a stop without hitting the carcass, which turned out to be part of a human body. Detectives searched the area and found body parts strewn along the eastbound tracks.
The working assumption is that another train hit a body somewhere down the track. Detectives continue to investigate.