On January 18, 2022, about 1100 central standard time, a Cessna 120 airplane, N90129, was substantially damaged when it was involved in an accident near Sturtevant, Wisconsin. The private pilot sustained serious injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. Security camera footage was obtained from the Sylvania Airport (C89), Sturtevant, Wisconsin. A review of the footage showed the airplane was attempting to depart to the east, using runway 08R. The takeoff roll was initiated and about a quarter way down the length of the runway, the airplane departed the runway to the left (north). The footage showed the airplane travel over a flat grass field with the engine running. The footage did not show the airplane become airborne at any time, and the tailwheel appeared to remain on the ground during the runway excursion. The airplane came to rest after it impacted the cabin of an unoccupied, parked fuel truck. The pilot reported he recalled taxiing for takeoff and applying engine power for the takeoff, however he was unable to recall any additional events. The airplane sustained substantial damage to the left wing, the left-wing lift struts, and the fuselage. Postaccident examination of the airframe revealed no mechanical anomalies. Flight control continuity and airframe to engine control continuity was established. The main landing gear brake lines sustained impact damage, which precluded a system brake test. The main wheels were found free to rotate, and the brake pads and rotors for both wheels showed minimal wear. No signs of foreign object debris jamming or restricting operation of the cockpit controls was noticed. The pilot had reported no medical conditions and no use of medications to the FAA. Ketamine, fentanyl, propofol, and lidocaine were administered in the prehospital and immediate stages of his hospital care. No note is made in the hospital documentation of any identification of underlying natural disease such as a stroke or heart attack that may have been affecting the pilot prior to the collision of his airplane with the fuel truck. Toxicology testing was performed by the FAA’s Forensic Sciences Laboratory on blood and urine left over from specimens obtained during the pilot’s initial hospital admission. The results included medications administered during his post-crash care including ketamine and its metabolite norketamine, fentanyl and its metabolite norfentanyl, lidocaine, and propofol. In addition, atorvastatin, famotidine, and fexofenadine were identified, which are non-impairing medications.