The Medical Examiner’s office said that a Schofield Barracks soldier died of carbon monoxide poisoning in March after he was found unconscious with a female companion in a vehicle in a Kaena Point ditch.

The Medical Examiner’s office said Christopher Holbrook’s death was accidental.

Holbrook and a 25-year-old woman were found on March 8 unconscious in the vehicle, which was stuck in about three feet of water with the engine running. Holbrook was declared brain-dead on March 13 and taken off life support systems three days later, according to police.

However, the medical examiner deferred a determination of the cause of death for a 32-year-old soldier pending the outcome of further tests that were completed this week.

A fisherman found the couple in a Jeep Wrangler on the Mokuleia side of Kaena State Park on a trail popular with offroad drivers.

The vehicle was in a ditch with its engine running, windows rolled up and muffler submerged in water. The fisherman removed both people from the vehicle and performed CPR on the man, who had no pulse and was not breathing. Police said a bystander had to break the back window of the Jeep to pull the unconscious couple out.

Other witnesses called 911 and assisted with the woman, who was unconscious but breathing. 

She was taken to the hospital for treatment.