A man, walking on a highway, was struck and killed by a semi this morning in eastern Iowa.

An Iowa State Patrol crash report shows 23-year-old John Riffle IV of Springville was crossing Highway 218 near Tiffin when he was hit by the northbound semi driven by 65-year-old Mark Meyer of Keosauqua.

It happened around 5:20 a.m. and investigators say, for now, they don’t know why Riffle was on the highway.