The National Transportation Safety Board has found pilot error was the cause of a 2004 plane crash in Kirksville that claimed the lives of thirteen of the fifteen people on board. The Corporate Airlines commuter plane went down shortly after 7:30 on the evening of October 19th, 2004, clipping treetops as it crashed about a mile short of the Kirksville Regional Airport runway. NTSB investigators say the pilot failed to adequately monitor his flight instruments as the plane approached the airport. The Board also found the pilot and co-pilot joked around in the cockpit, distracting them from their duties. The Board adds pilot fatigue played a role, as well, as the pilots had been working for almost fifteen hours and had made several landings that day in challenging weather.