As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PORTION OF THE NR 6 CYLINDER PISTON PIN PLUG BROKE OFF AND CAUSED THE PISTON TO DISINTEGRATE. THIS CAUSED DAMAGE TO THE CONNECTING ROD ON THE NR 5 CYLINDER AND DAMAGE TO THE CRANKCASE. NO RECOMMENDATION TO PREVENT THIS AT THIS TIME. (X)