On July 25, 1980, thirteen-year-old Sean Thomas Macintyre was on a boating trip near Thessalon, Ontario, when the vessel began taking on water near Cockburn Island and sank in the North Channel about two kilometres southwest of Bigsby Island. Occupants put on life jackets, but Sean slipped out of his life jacket during the chaos and disappeared beneath the surface. An official search and recovery was conducted but was unable to locate him.

Sean is presumed to have drowned and his body has never been recovered, leaving his family without closure.

Did anyone on the water near Cockburn Island that day remember the boat or the people involved?