A man traveling south with a group of snowmobilers was thrown from his vehicle onto Old Highway 51 and was killed in Mercer over the weekend. A 911 call said a man was lying unconscious on the roadway but was still breathing. The unidentified man was attended by Iron County Sheriff’s officers who responded to a call for help, but when they and the ambulance and snowmobile rescue team arrived, he was not breathing. Life saving measures were unsuccessful. The Iron County coroner and Wisconsin DNR were called to the scene. The cause of the crash is being investigated by the Iron County Sheriff’s Department.