On September 7, 2005, at 1530 central daylight time, a Piper PA-44-180 (Seminole), N291ND, owned and operated by the University of North Dakota, was substantially damaged during a wheels-up landing on runway 32 (3,002 feet by 60 feet, asphalt) at the Fertile Municipal Airport (D14), Fertile, Minnesota. Visual meteorological conditions prevailed at the time of the accident. The pilot and flight instructor were not injured. The instructional flight was operating under the provisions of 14 Code of Federal Regulations (CFR) Part 91 without a flight plan. The flight departed Grand Forks International Airport (GFK), Grand Forks, North Dakota, around 1400 and was operating in the traffic pattern at D14 when the accident occurred. The flight instructor reported that they were working on single-engine approaches and landings when the accident occurred. The flight instructor stated that a "midfield check was done and said, but was not verified." The flight instructor reported that "since we had heard the gear warning horn for so long during the airwork, I no longer noticed anymore." The flight instructor stated that they "did not do our final landing check" and that the airplane landed with "the gear in the up position."