At 1048 eastern time, a Cessna 172S lost its right wing while maneuvering in the vicinity of Monroe. The flight instructor and student pilot were killed. The flight had originated from Dekalb-Peachtree Airport 15 minutes earlier. A witness said she saw the airplane at about 1,500 feet in straight and level flight but was traveling very fast. She observed the nose pitch to 45 degrees nose-low and the airspeed increase more. The airplane was observed to start a spin to the right and turned about 180-degrees when a wing separated from the airplane followed by other pieces of the airplane. Another witness said she thought the pilot was performing a stunt maneuver until pieces of the airplane started falling to the ground.