As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(B-18711) AIRCRAFT ENROUTE, AFTER T/O AT FL015, NR 4 ENG HAD "BANG" SOUND AND SPOOL DOWN AND EGT OVER LIMIT. CREW FOLLOWED QRH TO SHUTDOWN ENGINE, DUMP FUEL AND AIR TURNED BACK. GROUND CHECK FOUND MANY METAL CHIPS IN TAILPIPE AND N1 ROTOR SEIZED. PRELIMINARY BSI FOUND 1ST STAGE HPT BLADES OUTER PART MISSING ALL AROUND, ONLY HALF THE BLADES FROM BLADE ROOT TO DISK IS AVAILABLE. THE ENGINE WAS REMOVED FROM SERVICE.