On October 26, 1995, at 1710 eastern standard time (est) a Piper PA34, N8LP, piloted by a commercial pilot was substantially damaged during a gear up landing on runway 18 (Dry asphalt, 5500'x100') at Terry Airport, Indianapolis, Indiana. The personal 14 CFR part 91 flight was not operating on a flight plan. Visual meteorological conditions existed at the time of the accident. The pilot reported no injuries. The flight departed Indianapolis, Indiana at 1705 est. During a telephone conversation with the pilot he stated that the aircraft had just been refueled prior to departure. The pilot said that during preflight he did not physically check the fuel caps for security. After takeoff the pilot noticed fuel venting from the left tank, and decided to return to the airport. A right hand traffic pattern was flown in an attempt to minimize fuel loss. The pilot stated that he did not complete his normal prelanding checklist, and could not remember if the gear warning horn sounded. Airport personal found the left fuel cap on the runway. Following the accident, the landing gear system functioned correctly.