On May 29, 1994, at 1500 mountain daylight time, a Cessna 182P, N8488M, landed hard at the Salt Lake City Airport, Salt Lake City, UT, during a local flight. Visual meteorological conditions prevailed at the time and no flight plan was filed. The airplane was substantially damaged and the private pilot was not injured. The operator of the airplane reported that on June 1, 1994, it was discovered that the airplane had been damaged. The operator stated that one propeller blade was damaged at the tip and bent slightly, the firewall was bent, and the floor board near the rudder pedals was wrinkled. The rental checkout logs indicate that the airplane was flown by the owner of the airplane on May 26. On May 27, the private pilot and a flight instructor flew the airplane. There were no discrepancies reported at this time. On May 28, the private pilot flew the airplane solo, with no discrepancies noted. On May 29, the private pilot again flew the airplane solo. At the conclusion of this flight, the operator stated that the private pilot did not check the airplane in as usual. The records indicate that the airplane was not flown by any other pilots from May 27 to June 1, when the damage was noted. The private pilot states that he does not know how the airplane was damaged.