DULUTH, Minn. — One man is dead after the boat he was piloting overturned in a turbulent Lake Superior Monday morning. 

It happened around 11 a.m. morning near Park Point in Duluth. The victim and two companions were out in a 21-foot aluminum boat helping a dredging crew. Investigators say the motor was overcome by water, leaving the boat at the mercy of rolling waves large enough to trigger Red Flag Warnings on the big lake. 

The boat flipped, throwing the three men into the water. 

Authorities say 59-year-old Donald Alan Slater and 50-year-old Randall Joseph Cortsen managed to make it to shore, but their co-worker remained unaccounted for. Search and rescue crews later located 68-year-old Donald James Sarter, 68, of Sturgeon Bay, Wisconsin, in shallow waters off the end of Park Point near Sky Harbor Airport. Sarter was pronounced dead on the scene. 

According to one of the survivors, all of the three men were wearing life jackets at the time of the incident but the preservers were not zipped.

The boat is owned by Roen Salvage of Sturgeon Bay, Wisconsin, where all three men were employed.