The Rock County Sheriff’s Office is looking into why the driver of a Ford Explorer crossed the center-line resulting in a head-on collision over the weekend.  The Sheriff’s office reports the two-vehicle crash happened about 7:00 a.m. Sunday on Highway 67 just southeast of Clinton.  Investigators say the Explorer was traveling east, and crossed into the path of a car driven by a 24-year-old man from Sharon, Wisconsin.  Deputies say the Explorer was fully engulfed in flames when emergency personnel arrived.  The male driver was pronounced dead at the scene.  The driver of the other vehicle was seriously injured.  Highway 67 was closed for four-hours because of the crash.