Police in Milton say the accident happened on Center Street just after 4:30 p.m. Monday.
Corporal Ken Royer said the 2003 Ford Coupe was dragged for about a fifth of a mile by the North Shore Railroad train
Officials said one 16-year-old girl was pronounced dead at the scene by the Northumberland County coroner's office.
Another 16-year-old girl was taken to a hospital, where she was listed in serious but stable condition.
The names of the victims have not been released. The accident is under investigation.