SALT LAKE CITY (AP) — Sheriff's deputies say altitude sickness appears to have caused the death of a Boy Scout during a camping trip in northeastern Utah.

Duchesne County Sheriff's Lt. Jeremy Curry said in a news release 17-year-old Douglas Julian of Salem lost consciousness and collapsed Saturday just as he and fellow scouts began hiking out to get the boy medical attention. Troop members began CPR but could not revive him.

Officials said an autopsy was planned to determine the exact cause of death.

Julian became nauseous and got a headache Thursday night and was still sick Friday, when the group decided to break camp in the High Uintas northeast of Duchesne.

A scout leader who hiked several miles to get cell phone service called for help, but Julian was already dead when a LifeFlight helicopter arrived.