At about 0930 Eastern time, the airplane was substantially damaged when it impacted trees and terrain. The Flight Instructor and Student pilot were fatally injured. Visual conditions prevailed. The airplane was performing touch and go landings in the airport traffic pattern. One witness observed the airplane bank left and cross in front of him. The left bank increased until the wings were straight up and down, then it just dropped straight towards the ground. Another witness observed the airplane during takeoff. She described seeing the airplane in a straight and level attitude. Then it banked left, and completed a U-turn. The airplane then pitched nose down, and descended quickly out of view.