An autopsy has found that a skydiving instructor was incapacitated by a premature chute inflation during an accident that killed him and his student.

The Dutchess County medical examiner says 25-year-old instructor Alex Chulsky of Brooklyn became paralyzed from a spine fracture. He also suffered an aortic injury.

The June 15 accident happened in Plattekill, in Ulster County.

Chulsky was strapped in a tandem harness with 49-year-old David Winoker of Chappaqua.

Winoker, who had three children, was buried on Father’s Day.

The Journal News says the parachute problem is known as a “hard opening.” The chute prematurely inflates and violently jolts.

It’s considered a rare occurrence.