Bear Lake, UT – A 22-year-old Salt Lake area man was killed by carbon monoxide poisoning over the weekend while boating on Bear Lake.

The Rich County Sheriff’s Office received a 911 call Saturday about 7:15 p.m. from a group boating on the lake, saying they thought one of their passengers was suffering from heat stroke.

Emergency crews met the boat as it docked at the Bear Lake State Park Marina. The man’s friends performed CPR as the boat was making its way to the marina, according to a statement from the sheriff’s office.

“EMS continued medical intervention for approximately one hour. In spite of all efforts, the victim was pronounced dead at the scene at (8:32 p.m.),” according to the statement.

The Utah State Medical Examiner’s Office conducted an autopsy and determined the cause of death to be carbon monoxide poisoning.

The group was in an older boat that did not have an outboard engine, according to the sheriff’s office. They believe the man was the only person on the boat who spent significant time near the rear of the boat, pulling skiers and swimmers out of the water, where the exhaust pipe was located. None of the other passengers on the boat suffered from carbon monoxide poisoning, according to the sheriff’s office.