The airplane was substantially damaged at about 1215 Mountain time when it impacted terrain while on final approach. The solo student pilot was killed. Visual conditions prevailed for the local supervised solo flight. After completing five or six uneventful takeoffs and landings, the CFI exited the airplane to watch the student conduct a solo flight in the airport traffic pattern. The flight was to consist of three takeoffs and landings. The CFI observed the student pilot conduct a touch-and-go landing before the wind shifted and the student pilot changed runways, conducting an uneventful touch-and-go landing. The third approach to landing seemed normal with the exception of being slightly high. The CFI then observed the airplane suddenly pitch downward from about 60 feet agl and descend out of sight below a hangar. The CFI then heard the sound of impact.