As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING INSPECTION THE COMPRESSION ON NR 1 CYLINDER WAS 67/80 AND THERE WERE NON-MAGNETIC PARTICLES IN THE OIL FILTER. CYLINDER NR 1 WAS REMOVED AND MANY PARTS OF THE PISTON HAD DISINTEGRATED AT THE TOP COMPRESSION RING. THE RING WAS BROKEN. THE TOLERANCE OF 0.010 INCH WAS FAR EXCEEDED, MAYBE IT WAS FRETTING BY THE TOP RING THAT CAUSED THE INCIDENT. THE CYLINDER AND PISTON WERE REPLACED.