On October 2, 2001, about 1310 eastern daylight time, a Beech C-45H, N8393H, was substantially damaged during a forced landing in Hudson, New Hampshire. The certificated commercial pilot, flight instructor, and passenger received minor injuries. Visual meteorological conditions prevailed for the instructional flight. No flight plan had been filed for the flight conducted under 14 CFR Part 91. The purpose of the flight was to conduct a flight review for the airplane owner, who occupied the left seat. A flight instructor occupied the right seat. According to a written statement from the pilot: "...the flight was normal up until approximately 2,000 feet on climb out. At that time, the left engine started to shake. Shortly after, the left engine failed, [and] the left propeller came to a complete stop." "[The flight instructor]...added power to the right engine, and vocalized that he would get the engine failure checklist. At this time, I was manipulating the controls. While he reached down to obtain the checklist located on the floor between us, I depressed the [right] engine feather button, [and] the right engine subsequently feathered. In the confusion, without confirmation from [the flight instructor]...I depressed the wrong feather button and feathered the wrong engine." "[The flight instructor]...vocalized and took command of the aircraft. [The flight instructor]...instructed me to start the right engine. Two attempts at restart were unsuccessful. It was necessary for me to conduct the restart procedure due to the fact that the starter controls are located on the left side, not accessible to him." "We were losing altitude rapidly; there were not many suitable landing areas. [The flight instructor]...located a golf driving range approximately 300 yards long. He successfully made an emergency landing into this area." According to a written statement from the flight instructor: "We departed Nashua airport and headed southeast, leveling off at pattern altitude approx 3 or 4 miles away, then started a slow climb, at approx 2,000 feet MSL, the left engine started to shake and shortly after the engine failed. I added power to the right engine and told...[the pilot] I would get the engine failure checklist. [The pilot]...was still flying the airplane. I reached down to get the checklist on the floor between us. After opening it to the proper section, I realized the airspeed was still decreasing. Then I found out,[the pilot]...had feathered the wrong engine, and didn't tell me. I told [the pilot]...I was taking command of the aircraft. He was badly shaking when I asked him to restart the right engine. We were losing altitude rapidly and [I] had to focus on flying the airplane. I found a golf driving range and made a successful emergency landing." In a follow up telephone interview, the pilot was asked why the engine was not restarted. He said the feathering button needed to be held down, but he was not familiar with the engine restart procedures and said he had never conducted an inflight restart. In addition, he said that after he had feathered the wrong engine, he "just froze." In a follow-up telephone interview, the flight instructor reported that during the landing, the right engine and firewall separated from the wing. When asked why the good engine was not unfeathered, and restarted, he replied that the feathering buttons for both propellers were located on the top of the left side glare shield in front of the pilot. Unfeathering the propeller required the appropriate feather button to be held in a depressed position until the propeller came out of feather and started rotating, and then, the feather button had to be pulled out to stop the propeller from going back into feather again. He reported that after the left engine lost power, and the right engine was feathered, he had to devote his full attention to the flying the airplane and picking a landing area. According to the pilots involved, the airplane owner's flight experience was 3,877 hours, with 872 hours in multi-engine airplanes, and 55 hours in make and model. The pilot had flown 10 hours in the preceding 90 days, with none in make and model. The flight experience of the flight instructor was in excess of 20,000 hours, with 16,000 hours in multi-engine airplanes, and 500 hour in make and model. He had flown 230 hours in the preceding 90 days, with 30 hours in make and model.