On October 31, 2016, at 1502 eastern daylight time, a privately owned and operated Piper PA-32-300, N3941X, was substantially damaged during a forced landing in Bartow, Florida. The pilot was not injured. Visual meteorological conditions prevailed, and no flight plan was filed for the personal flight that was operated under the provisions of 14 Code of Federal Regulations Part 91. The flight originated at Sanford International Airport (SFB), Orlando, Florida, and was destined for Bartow Municipal Airport (BOW), Bartow, Florida.According to the pilot, after entering a left downwind leg for the runway 05 traffic pattern at BOW, he reduced engine power and the airplane began to vibrate and shake. The engine then lost all power, while the propeller continued to windmill. He attempted to restart the engine using the emergency checklist procedures but was unsuccessful. He determined he would not be able to reach the runway and maneuvered toward a nearby pasture for an emergency landing. During the landing rollout, the airplane struck a fence damaging the left wheel hydraulic brake line which caused a loss of brake pressure. When he applied the brakes, he lost directional control and the nose landing gear collapsed. Examination of the airplane by a Federal Aviation Administration (FAA) inspector revealed that the firewall was damaged, and the fuselage skin aft of the firewall was wrinkled. An unmeasured amount of fuel was present in all four fuel tanks, and fuel was present at the fuel injector nozzles. Oil was present in the crankcase, and cylinder compression was attained on all cylinders when the propeller was rotated by hand. While rotating the engine, a grinding/crunching noise occurred once, but was not repeatable. The magnetos made noise consistent with rotation but were not tested for spark. The engine oil filter contained some particles. According to the FAA inspector, the engine had accrued about 2,060 total hours since overhaul, and the airplane had flown about 25 hours since the most recent annual inspection. The engine was examined again by a National Transportation Safety Board Investigator. After removal of the lower engine cowling, and removal of the top spark plugs, the engine's crankshaft was manually rotated. The crankshaft rotated without any signs of grinding. Thumb compression was attained on all cylinders. The oil "finger" screen was removed, it was clean and clear of debris. The No. 4 cylinder was removed to gain access to the case and view the crankshaft, camshaft and internal components. The push rods were clean, and no carbon or metal was present. There was no rust present in the cylinder, no scoring from rings or any signs of rubbing. The valves were seated and no traces of overtemperature. The pushrods and rockers were clean, lubricated, and no metal was observed. The piston and rings were clean and exhibited no marks. The connecting rod was clean, moved freely and was lubricated. The camshaft, crankshaft and internal components that could be seen from this opening were clean, with no corrosion and no metal particles visible. The oil filter was cut open during the previous examination and the filter case contained carbon deposits at the bottom of the filter case. Both magnetos were removed, manually rotated and produced spark from all leads. The fuel servo was removed and inspected for debris, the servo was clean and the finger filter was clear of debris. The air and fuel diaphragms were in intact with no tears or marks. The fuel filter in the mid center section of the airplane was removed for examination. It was also clean, absent of debris, and contained aviation gasoline. All fuel injectors were removed and inspected. They were all clean and absent of debris. The flow divider "spider" was opened for examination, it was clean and clear of debris and the diaphragm was intact. The air filter was removed and was also found clean and clear of debris.