peter kelly , a 34-year-old volunteer high school wrestling coach , was stabbed in the chest after he and a friend asked a group of rowdy fishermen to be quiet at a river on tuesday .
the two men were on the minnesota side of the river when they heard three men being loud and rude on the wisconsin side .
the group on the minnesota side was making statements like , ` why do n't you clean up your act ' , ' a captain steve smith with the polk county sheriff 's office in wisconsin .