JEROME, Idaho -

Investigators are trying to piece together what led to an Idaho man being struck and killed by a semi-trailer on Interstate 84.
   
The Times-News reports that 33-year-old Lyndon Buffington of Nampa had stopped in the median Tuesday morning before dawn and was outside of the vehicle when he was hit. Idaho State Police haven't been able to find the vehicle that hit him.
   
Police say Buffington's passenger, 32-year-old Malinda Buffington, drove off as the collision occurred. They didn't say how the Buffingtons were related or why the pair had stopped.
   
Lt. Robert Rausch said Tuesday that investigators were still trying to rule out the possibility that Buffington was injured before the crash or that there was some sort of foul play involved.