On August 5, 2005, about 0945 Pacific daylight time, a Cessna A185F, N4867C, registered to and operated by the pilot as a 14 CFR Part 91 personal flight, experienced a complete loss of engine power, followed by a ditching in Lake Washington, Seattle, Washington. Visual meteorological conditions prevailed at the time and the pilot was utilizing flight following. The aircraft was substantially damaged and the private pilot and his two passengers were not injured. The flight departed from Coolin, Idaho, about two hours prior to the accident. The flight was en route to Boeing Field, Seattle. In a written statement, the pilot reported that he had fueled the aircraft the day before with enough fuel for the two hour flight plus a one hour fuel reserve. The pilot reported that the en route portion of the flight was uneventful and a descent from 9,500 feet was initiated when clear of the Cascade Mountain range. The flight had descended to about 1,800 feet over the northeast side of Lake Washington, when the pilot had his first indication that something was wrong with the engine. The pilot stated that, "There were no sudden sounds; no choking or coughing of the engine. Rather it sounded as though someone had pulled the throttle all the way back - the normal sound (although I was at reduced power descending) just smoothly diminished to an idle sound over the course of about 1 second." The pilot made a turn to look for a landing spot and report to air traffic that he was having problems. Not seeing a suitable landing spot, the pilot opted to head toward Sand Point, an area located along the west shoreline of the lake, in hopes to reach an open field. During the descent, the pilot switched the fuel selector from "both" to the left fuel tank and then to the right fuel tank. The engine did not start and the pilot focused his attention on the emergency landing. The aircraft was unable to reach Sand Point, therefore, the pilot maneuvered for a ditching parallel to the shoreline. The aircraft collided with the water, remaining upright. All three occupants were able to egress from the aircraft uninjured, before it sank. A nearby motorboat operator rescued the occupants within minutes of the accident. The aircraft was recovered from the lake early the following week. The recovery personnel reported that approximately 16 gallons of fuel were drained from the entire fuel system. A small fuel leak was detected in the water. The engine and accessories were dried out in preparation for an engine run. The left side engine mounts were broken and subsequently secured. The auxiliary electric fuel pump was not functioning at full strength and was replaced with another. On August 11, 2005, in the presence of the National Transportation Safety Board Investigator-In-Charge and a Federal Aviation Administration Inspector from the Seattle, Washington, Flight Standards District Office, the engine was prepared for an engine run. After a fuel supply was added, using the same fuel that had been drained from the system, the engine was started without difficulty. Due to the damage to the engine mounts, and to the propeller controls from impact damage, the engine was run for several minutes at only a low power setting. A magneto check was accomplished and the fuel selector was moved from the "Both" position to "Left" and "Right." No anomalies were detected.