BEFORE DEPARTING YOUNGSTOWN, OH, THE PLT FILED 2 IFR FLT PLANS, 1 FOR A FLT TO PLATTSBURGH, NY, THE OTHER FOR A RETURN FLT FROM PLATTSBURGH BACK TO YOUNGSTOWN. AFTER A 2 HR & 10 MIN FLT TO PLATTSBURGH, 70 GAL OF FUEL WAS ADDED, BUT THE PERSON WHO SERVICED THE ACFT INDICATED THE TANKS WERE NOT FULL AFTER SERVICING. THE PLANE THEN MADE A 10 MIN FLT TO BURLINGTON, VT, BUT NO FUEL WAS ADDED AT BURLINGTON,,THE PLT THEN TOOK OFF ON A RETURN FLT TO YOUNGSTOWN. DURING THE DESCENT PHASE TO YOUNGSTOWN, THE PLT REQUESTED VECTORS TO THE CLOSEST ARPT. HE WAS PROVIDE VECTORS TO THE CHESS-LAMBERTON ARPT & ADVISED IT WAS 6 MI AWAY. A SHORT TIME LATER, THE PLT SAID THE ACFT HAD LOST POWER. SUBSEQUENTLY,IT CRASHED IN ROLLING, WOODED TERRAIN. DURING AN EXAM, NO FUEL WAS FOUND IN THE ACFT. NO OTHER EVIDENCE OF A MALFUNCTIONOR FAILURE WAS FOUND. WITH THE PASSENGER & CARGO LOAD, A MAXIMUM OF ABOUT 104 GAL OF FUEL COULD HAVE BEEN USED WITHOUT EXCEEDING THE CERTIFICATED GROSS WT OF THE ACFT. AT 45 TO 55% POWER, THE ACFT BURNED 17 TO 22 GAL PER HR. WND GSTS 30 KT