On January 27, 2023, at 0837 Pacific standard time, a Cessna T210N, N4758C, was substantially damaged when it was involved in an accident near Murrieta, California. The pilot sustained minor injuries and pilot-rated passenger sustained serious injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that he and his pilot-rated passenger were flying a 26-minute cross-country flight from Long Beach Airport (LGB), Long Beach, California to French Valley Airport (F70), Murrieta, California. The pilot reported that the preflight inspection of the airplane was normal, and that he physically looked in the left and right fuel tanks, which contained about 33 gallons of 100LL fuel per side before departing LGB. The pilot reported that he had completed an engine runup and observed normal engine rpm parameters during the propeller and magneto drop checks. The pilot reported that about 13 minutes into the 26-minute flight, he moved the fuel selector from the left tank to the right tank. When they approached the airport, the pilot retarded the throttle to near idle while descending, decreasing the airplane’s airspeed. He performed a near mid-field airport crossing from west to east and turned right to enter the downwind for a landing on runway 36. The pilot reported that while on the downwind leg of the traffic pattern, about 1,000 ft agl, he extended the landing gear, extended the flaps to 10°, trimmed the airplane for 90 knots, and made a right turn to the base leg of the traffic pattern. According to ADS-B data, during the turn from base to final the airplane’s airspeed was 80 knots at about 150 ft agl. The pilot reported that he manipulated the throttle to add power, but the engine did not respond. He cycled the throttle to troubleshoot the anomaly and turned on the auxiliary fuel pump. Despite his efforts the engine still did not respond, and the airplane descended into a ravine, impacted the ground, and nosed over about 2,000 ft short of the runway threshold. The airplane came to rest with the nose and spinner oriented to the west while the attached tail section was oriented to the east. The right wing sustained impact damage to the leading edge and the spar was fractured near the middle of the wing. The right-wing tank was breached, and the vented fuel cap was not present. The left wing’s leading edge sustained impact damage and the outboard 1/3 of the wing and aileron were folded underneath the wing. The left-wing tank was breached and the vented fuel cap was present and unremarkable. The fuselage remained intact, but the empennage sustained substantial damage. During a postaccident examination, an engine test run was conducted using an auxiliary gravity-fed fuel tank attached to the upper fuselage. During the first engine start attempt the engine would not rotate. Relays were audibly heard during the preparation of the engine start. Multiple impact-damaged circuit breakers near the battery position were then replaced to facilitate the engine run. An auxiliary power source was used to connect power to the starter relay, and the starter operated normally from the switch. The engine started successfully but ran with some hesitation and ultimately lost power. Further attempts to start the engine were unsuccessful. Engine control cable continuity was established to the instrument panel. The airplane’s fuel system revealed no anomalies with continuity from the left- and right-wing tank fuel lines to the fuel selector. Fuel system integrity was observed from the fuel selector through the manifold, and to each of the cylinder’s injectors, which were clear and free of impedance. Each of the six cylinder combustion chambers and piston heads were examined using a lighted borescope and revealed normal operational signatures. Each cylinder’s intake and exhaust valves were consistent with normal operation with no anomalies. The induction and exhaust systems were clear and free of any impedance.