A Missouri man was killed Saturday morning while crossing I-75 North, just south of Mt. Zion Road in Clayton County, police said.

John Scott Lewis, 22, was run over by more than one car as he attempted to cross the interstate just after 3:30 a.m., Clayton County police spokesman Sgt. Kevin Hughes said.

Two drivers stopped after hitting Lewis, and witnesses said he was already in the middle of the interstate when struck by those two motorists.

Hughes said late Saturday that investigators had not determined why Lewis was walking on the interstate.

—Angel K. Brooks contributed to this report.