On December 6, 1998, at 1601 eastern standard time, a Michael L. Thibault, RV-4, N62632, an experimental airplane, registered to the pilot, collided with a mailbox during an emergency landing near the Okeechobe Airport in Okeechobee, Florida. The personal flight was operated by the pilot under the provisions of Title 14 CFR Part 91 with no flight plan filed. A review of weather data recovered from the nearest reporting facility disclosed that visual weather conditions prevailed at the time of the accident. The airplane sustained substantial airframe damage, and the commercial pilot was not injured. The flight initially departed Okeechobee, Florida, at 1430. According to the pilot, on the morning of the accident he completed a preflight inspection of the airplane. After takeoff, the pilot flew 30 minutes in the local flying area before returning to the airport for closed traffic. The pilot reported that he had made several touch and go landings at Okeechobee Airport. While on final approach to runway 13, the pilot experienced a complete loss of engine power. The pilot elected to attempt an emergency landing on a public street. During the emergency landing, the right wing collided with a mailbox and a parked van. The post-accident examination of the accident site disclosed that the airplane rested in a ditch adjacent to the public street. The examination of the airplane revealed that fuel was present in the fuel system. Examination of the ignition system disclosed that the spark plugs displayed a clean ignition pattern. No obvious mechanical problems with the airplane were observed during the field examination. A review of existing weather data disclosed that weather conditions were favorable for the formation of carburetor ice. The pilot did not report applying carburetor heat during any phase of the flight.