On April 18, 1996, about 1530 eastern daylight time, a Cessna 310D, registered to 3SY AVN, Inc., landed hard at the South Fulton Airport, Palmetto, Georgia. Visual meteorological conditions prevailed at the time and no flight plan was filed for the 14 CFR Part 91 personal flight. The airplane was substantially damaged and the private-rated pilot and two passengers were not injured. The flight originated about 1505 from the Clayton County-Tara Field Airport, Hampton, Georgia. The pilot stated that he diverted due to a partially open cabin door. He entered the traffic pattern and while on short final approach to the 2,690-foot runway with a 600-foot displaced threshold, a high sink rate developed. He applied nose-up elevator input three times and only applied power during the third elevator application. The airplane landed hard on the right main landing gear causing it to collapse, then the airplane bounced twice. The airplane veered off the right side of the runway, and the nose and left main landing gears collapsed after contacting a closed taxiway raised 4-6 inches about 75 feet north of the runway. According to an A & P mechanic on the airport who witnessed the accident, propeller slash marks were first observed on the asphalt runway about 300 feet short of the displaced threshold and to the right of the runway centerline.