On April 15, 1995, about 1037 eastern daylight time, a Cessna 172M, N19901, registered to Aeromart of the Rock, crashed while landing at Wakulla County Airport, Panacea, Florida, while on a 14 CFR Part 91 personal flight. Visual meteorological conditions prevailed and a VFR flight plan was filed. The airplane was substantially damaged and the private-rated pilot and one passenger were not injured. The flight began from Panama City-Bay County International Airport about 1 hour 22 minutes before the accident. The pilot stated he reported to Tallahassee Approach Control that the airplane's engine was running rough. He then reported a total loss of engine power and declared an emergency. The pilot stated he was high, landed long, and rolled off the departure end of the runway. The airplane collided with a fence and telephone booth, resulting in substantial damage. Examination of the engine by FAA personnel revealed the number two cylinder's exhaust valve head separated from the valve stem for undetermined reasons.