As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING POST FDU SWAP RUN ON THE ENGINE, TECHNICIANS HEARD A "BANG" , FOLLOWED BY BLACK SMOKE FROM THE EXHAUST, NO INDICATION FLUCTUATIONS WERE NOTED. THE SUPPORTING SERVICE CENTER PERFORMED BORESCOPE INSPECTION AND FOUND MISSING 3RD STAGE IP ROTOR BLADE. DISASSEMBLY OF THE ENGINE CONFIRMED THAT ONE OF THE 3RD STAGE IPC ROTOR BLADES WAS MISSING.