Passengers on a flight to Salt Lake City were stunned on Sunday when a man on the plane suddenly died.

The man, believed to be in his 30’s, has not been publicly identified yet. Passengers say he was snoring loudly for a while before the plane landed and then suddenly was quiet.

“You could tell something was wrong. I asked, ‘Hey, sir, are you awake?’ ” passenger Jared Noall said. “I shook him a bit, trying to see if I could get a response out of him. We checked his throat for a pulse, and it wasn’t there, so we laid him down in the aisle and started CPR.”

Noall and two others on board attempted CPR for more than thirty minutes, but to no avail. Passengers were visibly distraught as they left the plane to go on to their destinations, say officials. An investigation is ongoing.

“They tried their very best; the family of the deceased man would be glad to know he did everything possible to revive him.” said fellow passenger Kevin MacIsaac. “It was sad to see the flight attendant remove his bag from the overhead rack — what shocking news for his family.”