Hatziri Nieva, a 17-year-old Hercules girl, and Ramon Prado-Santamaria, an 18-year-old Richmond man, had been walking on the tracks when they were struck by a train near Carlson Boulevard and Ohio Avenue.
Train No. 716 had left Oakland at 1:15 p.m. destined for Bakersfield. It struck the pedestrians at about 1:40 p.m., Amtrak spokeswoman Vernae Graham said.
The teens were pronounced dead at the scene, police said.
The Contra Costa County coroner's office has not yet determined whether the deaths were an accident or suicide, a deputy coroner said today.
The train was equipped with a video camera and the coroner's office is waiting for a copy of that video before making any conclusions about the deaths.