A 20-year-old male visitor died on Thursday after becoming distressed while snorkeling in waters off Waioli Beach Park, also known as Pine Trees, in Hanalei, Kauai officials said.

His identity is being withheld pending notification of next of kin.

Police say that shortly before 11:30 a.m., first responders were notified of a distressed snorkeler. Responding lifeguards found the man unresponsive in the water, and brought him to shore and began administering CPR. Hanalei firefighters arrived on scene and continued resuscitation efforts.

A visiting doctor at the beach during the incident also provided assistance.

AMR medics provided advanced life support while transporting the man to Wilcox Medical Center in critical condition. The man regained a pulse while in transport, but later died from his injuries Thursday night. An autopsy is pending.