MORRISTOWN, N.Y.—Authorities say a 57-year-old Pennsylvania man has died in a boating accident on the St. Lawrence River in northern New York.

State police say Christopher Tobiasz of South Williamsport, Pa., went water skiing on his boat with family members Monday afternoon on the river in the St. Lawrence County town of Morristown, 110 miles northeast of Syracuse.

Troopers say Tobiasz finished skiing and attempted to climb back into the boat when the propeller struck him in the leg. The people in the boat pulled him from the water and treated his injuries while they headed to shore.

He was taken by ambulance to River Hospital in Alexandria Bay, where he was pronounced dead.

Police say the cause of death is pending an autopsy.