Two Iowa men were killed in seperate snowmobiling accidents over the weekend. 27-year-old Donald Zitterich of Ames died Saturday after crashing his machine in northwest Iowa near Graettinger. Another wreck killed a Sumner man in northeast Iowa. Buchanan County authorities say 20-year-old Dusty Lee Brunscheon died Friday night after crashing a snowmobile near the Wapsipinicon River about a mile north of Independence.