A Northern Kentucky man was killed Saturday when he was struck from behind by a train in Grant County, according to local authorities.

Kyle Vallandingham, 20, of Fort Mitchell, died at the scene, the Grant County Sheriff's Office said in a news release.

Vallandingham and a friend were walking south on the tracks a mile south of Crittenden when a southbound Norfolk Southern train approached. The other man got off the tracks, but Vallandingham didn't.

The reason isn't clear; the case remains under investigation by the sheriff's office, the coroner's office and Norfolk Southern, said Christopher Lawson, a deputy coroner who handled the case.