On October 25, 1999, a chartered Learjet 35 business jet was scheduled to fly from Orlando, Florida, United States to Dallas, Texas, United States. Early in the flight, the aircraft, which was climbing to its assigned altitude on autopilot, lost cabin pressure, and all six on board were incapacitated by hypoxia, a lack of oxygen in the brain and body. The aircraft continued climbing past its assigned altitude, then failed to make the westward turn toward Dallas over North Florida and continued on its northwestern course, flying over the southern and midwestern United States for almost four hours and 1,500 miles (2,400 km). The plane ran out of fuel over South Dakota and crashed into a field near Aberdeen after an uncontrolled descent.