On June 25, 2010, at 1700 eastern daylight time, a Cessna 210D, N3973Y, registered to and operated by a commercial pilot, experienced a total loss of engine power and made a forced landing to a field in Robert Moses State Park, Babylon, New York. The personal flight was operated under the provisions of 14 Code of Federal Regulations Part 91, with no flight plan filed. Visual meteorological conditions prevailed. The certificated commercial pilot received minor injuries, and the airplane was substantially damaged. The flight originated from the Easton/Newnam Field Airport (ESN), Easton, Maryland, at 1545. The pilot stated that the engine began “running rough” approximately one hour into the flight. Shortly thereafter, the engine experienced a total loss of power, and the pilot reported to air traffic control that he was attempting to make an emergency landing. He landed the airplane in a field adjacent to a parking lot and the airplane collided with a railing. Examination of the wreckage by a Federal Aviation Administration inspector revealed that the airplane collided with a walkway railing, and buckled the left wing tip and left aileron. Examination of the airframe and flight control system components revealed no evidence of preimpact mechanical malfunction. Examination of the fuel system revealed no water or debris in the fuel or fuel system components. A cursory examination of the engine revealed that the number four cylinder connecting rod was fractured. The fractured connecting rod breached the top of the engine case below the number four cylinder. Further examination of the engine revealed there were only three quarts of oil in the engine sump, and a minimal amount of oil was noted on the wind screen. There were no oil deposits in the engine compartment or on the fuselage. The engine was removed and sent to for further examination.. During the engine examination, it was noted that the oil pump screen had been replaced with an oil filter adapter, manufactured by F&M Enterprises, Inc., patent number 5,291,863. The oil filter adapter was installed with a gasket between the pump and the adapter. Examination of the gasket revealed that it was torn. The copper crush washer at the top end of the adapter was not crushed. Oil leakage signatures were present at these two junctions. The crankshaft and counterweight assembly exhibited lubrication distress, thermal damage, and mechanical damage concentrated at the numbers two, three, four, five and six connecting rod journals. The number four connecting rod exhibited thermal damage, mechanical damage, and was fractured through at the base of the I-beam, separating both sections of bearing supports. Fragments of the number four cylinder connecting rod cap exhibited thermal and mechanical damage. The connecting rod bearings exhibited varying degrees of lubrication distress. A review of the logbooks did not show evidence of the installation or maintenance of the oil filter adapter. Further review of the logbooks revealed that the engine had an annual inspection eight months prior to the accident and had accumulated 18 hours of tachometer time. The logbook entry at the time of the annual inspection revealed that the engine was drained and refilled with 10 quarts of oil.