A witness, located on the shoreline, about three quarters of a mile from the accident site, reported that she observed the accident airplane arrive from the south and started to slowly reduce its altitude as it neared her position. The airplane appeared to be in controlled flight in its descent and the engine RPM was consistent with a cruising flight sound. The airplane continued to descend until it struck the water just before Falcon Rock, a large, exposed rock located offshore. A large wave crashed over the airplane, and it disappeared under the water. The wreckage was not located. The pilot is presumed fatally injured and the airplane destroyed. A friend of the pilot reported that the pilot was diagnosed with a terminal illness and added that the pilot did not want to be in a hospital or a care facility and preferred to die in his house or his airplane.