Three teenagers are dead and another suffered serious injuries as a result of a one-vehicle crash on Friday afternoon between Rexburg and St. Anthony.

Idaho State Police said the four teenagers were traveling in a 2000 Suzuki Grand Vitara compact SUV westbound on Highway 20 around 3:10 p.m. when the vehicle left the roadway for unknown reasons and overturned.

State police said the teens were not wearing their seat belts and all four were ejected from the vehicle during the crash.

One of the teens died at the scene while two others died at Eastern Idaho Regional Medical Center in Idaho Falls where they had been transported — one by ambulance and one by emergency helicopter — following the crash.

The fourth teen was transported by ambulance to Madison Memorial Hospital in Rexburg for treatment of serious injuries. That teen was later transferred to EIRMC. A condition update on that individual has not yet been released by authorities.

The teens were all from St. Anthony and were the only occupants of the compact SUV. State police have not yet released their names.

The eastbound lanes of Highway 20 as well as one of the westbound lanes were blocked for three hours because of the crash.

The accident remains under investigation by state police.