ACCORDING TO THE PLT, THE ENG BGN RUNNING ROUGH DRG FLT, THEN CLRD & RAN SMOOTHLY AGAIN. HE RPRTD HE ELECTED TO ABORT THE FLT & MADE A TURN, THEN SVRL MIN LATER, THE ENG LOST PWR. DRG AN EMERG LNDG IN A PARKING LOT, THE L MAIN GEAR HIT ANAUTO & FATALLY INJURED THE DRIVER. BFR COMING TO REST ON AN EMBANKMENT, THE ACFT HIT 2 OTR AUTOS & A GUY WIRE. WITNESSESRPRTD THE ACFT WAS CIRCLING THE AREA BFR THE ENG LOST PWR. A FRIEND OF THE PLT WAS LIVING APRX 2 BLKS FM THE ACDNT SITE.NO PREIMPACT PART FAILURE/MALFUNCTION WAS FND. DRG A POST-ACDNT CHECK, THE ENG OPERATED NORMALLY. AN INV REVEALED CONDS WERE CONDUCIVE TO CARBURETOR (CARB) ICING. THE PLT MADE NO MENTION OF SPECIFICALLY USING THE CARB HEAT DRG THE EMERG. ALSO, THE INV REVEALED THE PLACARD FOR THE FUEL SELECTOR (SEL) WAS DESIGNED TO RESTRICT MVMNT OF THE SEL TO THE L & RGT PSNS (NO 'OFF' PSN), BUT THE PLACARD WAS FND OUTSIDE THE ACFT WITH NO DMG. SEL WAS FND IN A PSN THAT WLD HAVE SHUT OFF FUEL TO THE ENG. THE PLT RPRTD HE SHUT OFF THE FUEL WHEN HE WAS COMMITTED TO LND. FLT TIME SINCE ANNUAL INSPN: 4.4 HRS.