On August 21, 2004, at approximately 1955 mountain daylight time, a Piper PA-24-250, N5975P, piloted by a private pilot, was destroyed by fire when the landing gear collapsed during landing at Sterling Municipal Airport (STK), Sterling, Colorado. Night visual meteorological conditions prevailed at the time of the accident. The personal cross-country flight was being conducted under the provisions of Title 14 CFR Part 91 without a flight plan. The pilot and passenger were not injured. The flight originated at Imperial, Nebraska, at approximately 1915. According to the pilot, after several attempts to extend the landing gear, he manually extended the landing gear and noted a "green" landing gear indication. After a "slow" landing, and a "brief" rollout, the landing gear collapsed. The airplane settled onto the runway, slid approximately 200 feet and came to a stop on the runway centerline. Within a few moments a fire ensued, destroying the airplane. According to an FAA inspector, a witness stated that the airplane landed on its tires and then rolled several feet before the landing gear collapsed. The inspector stated that, the pilot reported having landing gear problems prior to the annual inspection which was completed on July 16, 2004. The inspector also stated that the pilot had received instruction from a mechanic on how to manually lower the landing gear. The inspector added that the pilot reported that he had not had any further problems since the annual, which included approximately 12 to 15 landings. An examination of the airplane, by the FAA inspector, revealed no anomalies.