On October 2, 2023, about 1250 Pacific daylight time, a Cessna 340A airplane, N121CB, was substantially damaged when it was involved in an accident near Hayward, California. The pilot and passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that the airplane was parked next to his hangar and that he had just started the engines for the upcoming flight. He turned on the avionics and shortly thereafter lost consciousness. The airplane started moving onto taxiway A and into the runway safety area next to the runway. The nose landing gear collapsed and the engines came to a stop. The pilot woke up at the accident site and shut off the fuel and avionics. The pilot’s wife, who was the passenger, attempted to wake him up while the airplane was in motion. On arrival to the emergency department, the pilot was awake and alert with no recollection of the event. He denied any prior chest pain or dizziness. He did report that in February 2023, about 8 months before the accident, he had been evaluated for an acute illness and had undergone an ECG that had been abnormal. He had been referred for a cardiac stress test by his primary care physician but had not completed it by the time the accident occurred. The pilot, who held a Class 3 medical certification from the FAA without waivers, was evaluated by a cardiology provider in the emergency department, who reviewed the ECG and noted findings consistent with a possible previous heart attack but saw no definitive changes indicating a current heart attack. The cardiology provider documented that the pilot’s elevated troponin was likely the result of a recent arrhythmia, as the pilot did not have a history of chest pain. The cardiology provider stated that it seemed likely that the syncopal episode was the result of some kind of acute arrhythmia. The pilot was admitted to the hospital for monitoring overnight and discharged with follow-up appointments the next day. On follow-up with the cardiologist, the pilot underwent a cardiology evaluation that included a Holter monitor, cardiac MRI, stress test, and cardiac catheterization. The catheterization found significant coronary artery narrowing that was treated with percutaneous transcatheter angioplasty and placement of a coronary artery stent.