Many questions still remain about the late August crash of a passenger jet on takeoff from Lexington, KY, but some of the early answers aren’t encouraging.

Forty-nine of the 50 people on board Comair Flight 5191 died when the pilot mistakenly attempted to take off in darkness from an unlighted runway that was too short. The CRJ-100 jet crashed into a fence and trees past the end of the runway.

The pilots should have used a much longer, lighted second runway. But that wasn’t the only problem. Early investigation revealed that there should have been two air traffic controllers on duty – one to monitor air traffic on radar and a second to perform other tower functions.

Only one air traffic controller was on duty at the time of the crash and that person was performing both functions – on two hours’ sleep. Another unusual event occurred before the jet even began taxiing. The flight crew somehow boarded the wrong aircraft and turned on the power before they were informed they were on the wrong plane.

After clearing the aircraft for takeoff on the proper 7,000-foot (2,133 meter) runway, the controller turned his attention to paperwork and had his back to the jet. He did not know that the Comair plane had turned onto a runway that was only 3,500 feet (1,067 meters) long – insufficient for the jet to get airborne safely. It crashed into a fence and trees and burst into flames. Only the plane’s co-pilot survived. He was critically injured.

Although it will be some time before all the elements behind this tragic incident are known, it already carries some valuable lessons for supervisors. First, it’s essential for people in safety-sensitive positions to not be suffering from severe sleep deprivation and second, when two people are required to safely perform an operation, trying to do so with just one person can be a fatal mistake.