On May 8, 2004, about 1700 eastern daylight time, a Cessna 170B, N1754D, experienced a loss of engine power, and was destroyed after a forced landing in Shirley, New York. The certificated private pilot was not injured. Visual meteorological conditions prevailed and no flight plan had been filed for the flight that departed Brookhaven Airport, Shirley, New York. The personal flight was conducted under 14 CFR Part 91. According to the pilot, he conducted a preflight inspection of the airplane and departed for a local flight. Approximately 20 minutes after takeoff, he noticed a drop in engine oil pressure and RPM. Shortly thereafter, the engine lost all power and the pilot performed a successful forced landing to a parking lot. After landing, the pilot exited the airplane and observed smoke and fire emanating from the cowling. He also observed that the engine cowling plugs were still in place. The fire spread and consumed the airplane. Examination of the of the engine did not reveal any pre-impact mechanical malfunctions. Nor did the pilot report any.