A West Virginia woman died last night after her car and a tractor-trailer truck collided on Interstate 79 in Franklin, Greene County, state police said.

Stephanie R. Warner, 19, of Buckhannon, had been driving south on I-79 at about 10:10 p.m. at a high rate of speed when she lost control of her Ford Escort, police said.

For unknown reasons, her car swerved into the grass median, back onto the southbound lanes, and into and across the median into the northbound lanes.

Her driver's side door was struck by a northbound tractor-trailer truck, driven by George M. Wienand of Parkton, N.C., police said.

State police are investigating what caused Ms. Warner to lose control of her vehicle.

Mr. Wienand was not injured.