(Iron County, UT)  –  The driver of a semi-truck that rolled on State Route 56 in Iron County wasn’t wearing his seatbelt.  That’s according to the state Highway Patrol, who said yesterday Morris Carter’s truck drifted off the highway Wednesday afternoon and then rolled when he over-corrected.  Carter died at the scene.  Investigators are still trying to figure out what caused him to drift, according to The Spectrum. Â