At 12:10 Pacific time, a Beech BE-55 landed gear-up at San Bernardino. The instructor and student were not injured. The student told police he was receiving flight instruction for his commercial certificate and had just completed two touch-and-go takeoffs and landings. He was on his third touch-and-go to runway 24 when he forgot to lower the landing gear prior to touchdown. The instructor said he did not hear the gear warning horn prior to the accident.