A Virginia motorcyclist died early Tuesday when he was struck by a tractor-trailer on Interstate 95 in Fairfax County, police said.

Timothy E. Halpin, 68, of Dumfries, Va. was in the left northbound lane when he lost control of his motorcycle about 4:30 a.m., according to the Virginia State police. Halpin fell off the bike and slid into the center lane, where he was hit by the truck, police said. They said it was raining at the time of the crash.

Police said the driver of the tractor-trailer did not stop, and that witnesses were unable to provide a detailed description of the truck.

Halpin died at the scene, and the incident is still under investigation, they said.

Police are asking that anyone with knowledge of the crash contact the Virginia State Police at 703-803-0026.