On January 22, 2004, at approximately 1916 mountain standard time, a Beech A36, N8240U, was substantially damaged when it impacted a building following a loss of engine power and subsequent forced landing during a visual approach to Four Corners Regional Airport (FMN), Farmington, New Mexico. The private pilot sustained serious injuries. Night visual meteorological conditions prevailed at the time of the accident. The local personal flight was being conducted under the provisions of Title 14 CFR Part 91 without a flight plan. The flight originated at approximately 1910. According to a representative from San Juan Pilot Training, Inc., the pilot departed Farmington at approximately 1500 for a 3-hour cross-country flight to Canyonlands, Utah, Page, Arizona, and then back to Farmington. The pilot returned to the Farmington area at approximately 1800. Upon his return, the private pilot contacted the tower and requested clearance to do take-offs and landings. He completed nine take-off, and landings on runway 25. Each landing was a full stop, taxi-back, and subsequent take-off (as required by a local training policy). At approximately 1910, the pilot contacted the tower and asked for clearance to take-off and fly the pattern for a tenth time. At approximately 1915, the pilot reported that he had lost engine power. According to witnesses, the airplane was flying at a low altitude when its wings began to dip side to side. The airplane then pitched nose-up, rolled over, dove, and struck the roof of a police station. The impact crushed the nose section aft, and the leading edge of both wings. An examination of the airplane at the scene showed that approximately 3 to 5 gallons of fuel had leaked from the airplane's tanks. The fuel selector lever was in the "left tank" position. A subsequent examination showed approximately 4 gallons of fuel in the right wing tank, fuel in the fuel strainer and filter, and no fuel in the lines. Flight control continuity was confirmed and an examination of the engine and other airplane systems showed no anomalies. According to the aircraft manufacturer, using a fuel calculation of 15 gallons per hour, and a total flight duration of 4.4 hours, the total calculated fuel used would be 66 gallons. Total useable fuel for the airplane is 74 gallons.