The owner of a marine towing company, based in Sturgeon Bay, died Monday morning as a result of a boating accident on Lake Superior. Sixty eight year old Donald Sarter and two employees, 50-year old Randall Corsten of New Franken and 59-year old Donald Slater of Sault Ste. Marie, Michigan, were in a 21-foot boat on Lake Superior near Duluth, Minnesota when wave action affected the motor and caused the vessel to capsize, throwing all three into the water. Corsten and Slater were able to swim to shore and alerted authorities. They were not injured. Sarter was later found in shallow water and pronounced dead at the scene. All three were wearing life jackets. Weather conditions at the time caused local authorities to issue a red flag warning, meaning smaller boats were told to avoid going out onto the lake. The Saint Louis County Sheriff’s Office indicated that the investigation into the boating accident was continuing. Sarter, who recently purchased the former Selvick Marine Towing Company, had been a tugboat captain on the great lakes for more than four decades.