Erika Kruger, 16, of Helena, was killed in a single-vehicle crash 3 miles west of Drummond on Wednesday night.
Granite County Sheriff/Coroner Scott Dunkerson said two people were in the car during the crash. Both were thrown from the vehicle, and Kruger died on the scene from blunt force trauma.
Montana Highway Patrol Trooper Tim Wyckoff responded to the scene. "They were headed east on I-90 and the car drifted onto the shoulder and then over corrected across both lanes and went into the median," Wyckoff said. The car then hit an authorized vehicle turnout, sending it airborne and into the westbound lanes, rolling and ejecting both occupants.
Wyckoff said alcohol and drugs were not suspected in the incident. Kruger was not wearing a seat belt.
The other person, a 23-year-old man, was flown to Missoula for treatment for what Dunkerson called "life-threatening injuries."
Editor's Note: This story has been updated to correct Erika Kruger's age.