Smoke reduced visibility along U.S. Highway 36 in Caldwell County Thursday, contributing to a crash that left an 83-year-old man with serious injuries.

The Missouri State Highway Patrol crash report says Richard Thorsen of Bevier rammed his pickup truck into the rear of a tractor-trailer that had slowed for the smoke four miles west of Breckinridge.

Mr Thorsen was transported to the Truman Medical Center in Kansas City.