After flying about 200 miles from his home airport, the pilot performed an uneventful night landing. After taxiing to the end of the runway he decided to perform another takeoff and landing for night currency. There was no traffic in the pattern, and after takeoff he retracted the landing gear. Once at pattern altitude, he stabilized the airplane in preparation for landing on the longest runway. During the final approach he adjusted the throttle, mixture, flaps, and propeller, but missed the step to extend the landing gear. The pilot stated that during the landing he did not recall hearing the gear warning horn, although it had worked during the preflight inspection. The airplane landed gear-up about midfield down the runway and sustained substantial damage to the lower fuselage structure. Following the accident, the pilot secured the airplane by shutting off the fuel selector valve and turning off the airplane’s master switch (which also controlled its external lights). The airport served air carrier operations and was located within Class D airspace until 2000 local, one hour before the accident, when the air traffic control tower closed, and the airspace reverted to Class G (uncontrolled). About the time of the accident, an Embraer E175 air carrier flight was inbound for landing on the accident runway, but from the opposite direction. A member of the airport operations department was performing a routine wildlife runway inspection and observed the accident. He warned the inbound air carrier flight that the runway was obstructed, and the crew initiated a missed approach, and diverted to another airport. The first officer from the air carrier flight stated that he heard the accident airplane make position announcements while in the pattern, but that had it not been for the announcement by airport operations personal that the runway was obstructed, they would likely have continued the approach and landed with the unlit airplane still occupying the runway. The airport typically served about 218 air carrier flight takeoffs and landings per week during the period of the accident, 13 of which were due to operate after the control tower was closed.