At 1033 Eastern time, the airplane impacted up-sloping terrain and was destroyed. The commercial-rated pilot and four passengers were fatally injured. The flight originated about 1029. Visual conditions prevailed. Witnesses reported the airplane landed at approximately 1001 hours, taxied to the south side of the airport, and without securing the engine, boarded two waiting passengers. The airplane then was observed taxiing towards a runway, but an airplane was being towed on the taxiway at that time. The accident airplane turned around and taxied to the opposite end of the same runway and began its takeoff roll. A pilot-rated witness reported the airplane became airborne when it was / down the runway. The witness reported the airplane did not appear to be climbing very well and continued on the runway heading for approximately one mile. Other witnesses observed the airplane flying “exceptionally low.” After being reported overdue, the airplanes wreckage was located at approximately 1900.