A 50-year-old visitor from California died of an apparent drowning Monday afternoon while snorkeling in waters off Poipu Beach, according to the Kauai Police Department.

A call was made to KPD’s Dispatch Center around 2 p.m. indicating that a man, later identified as Mack Lewis, was found unresponsive in the sandbar off the beach.

Kauai Fire Department personnel from the Koloa fire station, lifeguards and an American Medical Response ambulance were notified and immediately responded, police said. Attempts to revive Lewis were unsuccessful.

He was transported to Wilcox Medical Center where he was pronounced dead. An autopsy is scheduled to determine the exact cause of death, police said.

Volunteers with Life’s Bridges, a grief counseling service, were contacted to offer support to Lewis’ family and friends.