At 15:00 EST, a Mooney M20J was damaged during a forced landing near New Milford. The pilot was not injured. The pilot said the airplane had experienced a propeller strike in September, and the engine was sent to the manufacturer for a teardown inspection. On the day of the accident the pilot arrived at Danbury to see if the airplane was ready to be flown after having the original engine and a new three bladed propeller installed. The engine had been test run for 0.4 hours without producing any leaks or anomalies. The pilot completed extensive run-up checks and was cleared for departure. The takeoff was uneventful, and the pilot executed a closed traffic pattern to a touch-and-go. He departed the traffic pattern to do some airwork north of the field. All maneuvers were completed without any problems or changes in the running of the engine. After being airborne for approximately 25 minutes, and while in cruise flight at 3,000 feet msl, the pilot heard a loud bang, and white smoke immediately filled the cockpit. The pilot declared an emergency. He heard a second bang and the engine seized. The pilot decided to land in one of several playing fields behind a high school currently under construction. The pilot overshot the first field and set up for the second field. The airplane did not touch down until near the end of the field. He struck piles of dirt that bordered a creek at the end of the field and the landing gear sheared off. The engine had holes in the crankcase along with broken connecting rods.