Authorities say a New York City man who drowned at the Jersey Shore last weekend suffered a seizure while swimming.

John Crimmins was with friends in the ocean off of Mantoloking when he suddenly disappeared from their sight around 2:30 p.m. Saturday.

An extensive search was launched, and the 22-year-old Yonkers resident was found in the surf less than an hour later. He was pronounced dead at a hospital short time later.

The Ocean County Prosecutor's Office says their investigation determined Crimmins had a medical condition that caused seizures. They say his death has been ruled a drowning, with idiopathic epileptic seizures contributing to the event.

Crimmins was the stepson of a New York schools superintendent.