As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT REPORTED A STRONG VIBRATION FOLLOWED BY A LOUD MECHANICAL BANG IN THE ENGINE DURING FLIGHT. SECONDS LATER THE ENGINE ABRUPTLY STOPPED. AN ENGINE 'TEAR DOWN' INSPECTION WAS PERFORMED AND REVEALED THE CRANKSHAFT BROKE AT THE NR 4 'CRANKSHAFT MAIN BEARING JOURNAL'.