On July 1, 2023, about 1030 Pacific daylight time, a Piper PA-28-140 airplane, N4586R, was destroyed when it was involved in an accident near Lake Tahoe, California. The pilot was not injured and the passenger sustained serious injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal cross-country flight. The pilot reported that the airplane was just purchased in Southern California and that he and his passenger were relocating it to Carson City Airport (CXP), Carson City, Nevada. They departed on the accident flight from Modesto City-County Airport-Harry Sham Field (MOD), Modesto, California, and followed the interstate highway while approaching the west side of Lake Tahoe. After reaching the Lake Tahoe area, the pilot decided to perform a flight around the lake before continuing to his destination, which was on the east side of the lake. While adding power to level off at 9,500 ft, he heard and felt a pop in the throttle handle and the rpm decreased to 1,800. Subsequently, the throttle was not controlling the engine power and the rpm decreased to near idle. The pilot added full rich mixture and switched fuel tanks. Despite his actions the engine would not increase in power. The pilot made a radio call and pitched for best glide over the lake. The airplane nosed over after contacting the water; the pilot and passenger egressed and were soon rescued by nearby boaters. A security video captured the airplane during its descent over the water. The airplane contacted the water and flipped over in a big splash. Soon after, nearby boats were seen responding. The search efforts did not locate the airplane and the wreckage was not recovered. Review of the airplane's maintenance logbooks revealed that the last annual inspection was completed on April 9, 2022. At that time the airplane had a total time of 2,976 hours. The investigation was unable to determine how much time was put on the airplane since the last inspection.