The airplane was destroyed on impact with terrain and a postaccident fire while approaching to land. The airplane was piloted by a student pilot. A postaccident examination of the airframe and engine failed to reveal any anomalies that could be associated with a preexisting condition. A weather report for a nearby facility listed few clouds at less than 100 feet. A witness reported fog and a visibility of less than 1/4 mile with "...virtually no ceiling" at the accident airport.