Police in Schuylkill County say the vehicle was heading north on Interstate 81 in Butler Township when it left the road about 2:15 a.m. Saturday.
Police at the Frackville barracks say the vehicle then went about 300 feet along the grass median, struck a dirt embankment, and flew 100 feet before running into the concrete bridge support beneath the interstate.
Authorities say 57-year-old Mamon Simard, 54-year-old Danielle Joncas and a 17-year-old girl were pronounced dead at the scene. None was wearing a seat belt. The 52-year-old driver and a 60-year-old passenger were treated for broken bones.