On this day in history in 1999, golfer Payne Stewart and his agent boarded a SunJet Aviation Learjet 35 from Orlando bound for Dallas. During the climb, the aircraft quickly lost pressure and everyone quickly caught hypoxia, a lack of oxygen. The plane climbed past planned altitude and failed to make the westward turn towards Dallas. ATC quickly caught on to what was happening and sent 3 intercepts out, all reported they saw no movement inside the aircraft. The aircraft eventually ran out of fuel and quickly spiraled down over South Dakota near Aberdeen.
The ultimate cause was hypoxia along with the incident checklist not stating that putting on oxygen masks first was priority. We sadly lost one of the greatest golfers in MLG history.
The aircraft before its final journey

Credits: Wikipedia, Air Crash Investigation, and Allec Joshua Ibay
Thank you all, and may all 6 on board Rest In Peace.