An Oklahoma man died and three others were injured Sunday when the pickup he was driving left Interstate 70 for an unknown reason and crashed in Russell County.

Kansas Highway Patrol reports the driver was 21-year-old Steven C. Greenwood of Burneyville, Oklahoma.

Greenwood was driving an eastbound 2005 GMC that went off the Interstate 7.1 miles west of U.S. 281, at 2:54 p.m. The pickup entered the south ditch and struck the guard rail. It then flipped over the guard rail and rolled several times, coming to rest of its wheels.

Greenwood was taken to Hays Medical Center. KHP reports he was not wearing a seat belt at the time of the crash.

There were three other occupants in the pickup and all of them were taken to the hospital in Hays with undetermined injuries. Jesse D. Dominguez, 23, from Marietta, Okla., and Tyler L. Bates, 22, from Ardmore, Okla., were both wearing seat belts; Joseph A. Boatner, 22, from Marietta, Okla., was not.