SLATER, Iowa—A Madrid man was injured last Thursday afternoon when the snowmobile he was operating tipped over near Slater.  Michael Hassebrock, 51, was operating his snowmobile on a trail when he made a 90-degree turn into a ditch and the snowmobile flipped.  He suffered an injury to his chest and was transported by ambulance to Mary Greeley Hospital in Ames.  He was wearing a helmet at the time of his accident.  The accident occurred about 3:30 in the afternoon.  The Iowa Department of Natural Resources conducted the investigation into the accident, which occurred in Story County.