The 10,000-hour flight instructor and a commercial pilot receiving multi-engine instruction were conducting local multi-engine training. After the upper airwork portion of the flight was completed, the flight proceeded to a nearby airport to practice single-engine approaches and landings. Following the student's demonstration of an engine shutdown and restart procedure, the flight instructor asked the student to leave one engine at idle power for a simulated single-engine landing. During the first approach and landing, the flight instructor stated the student appeared to be on a stable approach to land on Runway 30 (a 3,005-feet long by 60-feet wide asphalt runway); however, when the airplane crossed the landing threshold, while at approximately 50-feet above the ground, the student pitched the airplane up and yawed the airplane approximately 45-degrees to the right. The flight instructor stated that he took control of the airplane and pushed the nose of the aircraft down as he applied right rudder. Despite his effort, the airplane impacted the runway hard. The left main landing gear collapsed causing the airplane to exit the left side of runway. The pilot receiving multi-engine instruction was reported to have accumulated a total of 25-hours in twin engine airplanes. The flight instructor reported that at the time of the accident, the winds at the airport were 'light and variable.' Additionally, he also reported there were no mechanical failures or malfunctions.