Officials say one of a couple of things could have caused the diving incident that claimed the life of 24-year-old New Bern resident James Alexander, but his death has been ruled as accidental.

National Park Service Deputy Director Mike Anderson said Alexander and his twin brother David were free diving in Salomon Bay in St. John, U.S. Virgin Islands, on Friday. The brothers had hiked just under a mile on the beach to get to the diving spot.

Alexander's body was found at the bottom of the water at a depth of 35 to 41 feet. Drug or alcohol use was ruled out, park service officials said.

Anderson speculated that the drowning could have resulted from a shallow-water blackout. He said divers sometimes lose consciousness caused by cerebral hypoxia, or reduced oxygen to the brain, toward the end of a dive, and the diver does not experience an urge to breathe.

Anderson also said that Alexander could have taken deep breaths before diving and could have hyperventilated. He said a swimmer who is fit and strong probably is unaccustomed to such a situation.

"They tried everything that they could to save his life. A park ranger attempted CPR but could not revive the young man," Anderson said.

Alexander is the son of Nancy Alexander, director of the MERCI Clinic in New Bern, and Dr. George Alexander, a heart surgeon.

Anderson said the family was still at St. John on Wednesday, and due to customs, has to go through a number of proceedings to bring their son's body home. Pollock-Best Funerals & Cremations of New Bern is handling the arrangements.

The twins were 2006 graduates of Parrott Academy. Both enjoyed the outdoors and volunteered for community service projects. James Alexander was an Eagle Scout, North Carolina Scholar, athlete and an honor student.