The pilot reported that, during final approach, the engine sputtered then had a total loss of power. The airplane landed short of the runway on the threshold, and the nose landing gear collapsed. The airplane sustained substantial damage to the engine truss and mount. A postaccident examination by a Federal Aviation Administration (FAA) airworthiness inspection did not show any evidence of preimpact mechanical malfunction or abnormalities. A photograph provided by the inspector, shows no damage to the propeller, which is consistent with the engine not producing power at the time of impact. He added that fuel was present in the tanks and that the gascolator screen was found clear of debris, and he suspected carburetor ice was responsible for the loss of engine power. The automated weather observation station located on the airport reported that, about the time of the accident, the wind was 310° at 7 knots, 7 statute miles, temperature 72°F, dew point 48°F. The airplane landed on runway 34R. According to the Carburetor Icing Probability Chart (refer to docket) and based on the temperature and dew point about the time of the accident, the conditions were favorable for serious carburetor icing at decent power setting. After multiple attempts, the pilot did not submit the National Transportation Safety Board Pilot/Operator Aircraft Accident/Incident Report Form 6120.1.