UNDATED, WI (KDAL) - The Wisconsin Department of Natural Resources Friday renewed a call for snowmobile safety after three more deaths in two days. That brings the official total of Wisconsin snowmobile deaths this season to 15, which is five more than last season's total. Officials said two people apparently en route to Madeline Island were found dead in the South Channel of Lake Superior after leaving Bayfield. That happened late on Wednesday or in the early morning hours Thursday. Then later on Thursday, conservation wardens responded to a single fatality on the Oconto County trail. Both cases are under investigation. Conservation Warden and Snowmobile Safety Administrator Gary Eddy said most of these deaths have involved excessive speed, alcohol or night-time operation. DNR officials are urging extra caution as the weather warms, including to stay off the ice altogether.