As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT RETURNED TO LANDING REPORTING NOISE AND VIBRATION IN NR 1 ENGINE. AFTER SEPARATING FREE TURBINE FROM ENGINE DISCOVERED ONE EACH SECOND STAGE N1 TURBINE BLADE MISSING FROM ROOT OUT. DOWNSTREAM DAMAGE IN FREE TURBINE. BOTH COMPRESSOR AND FREE TURBINE REPLACED. COMPRESSOR IS BEING SHIPPED TO THIS REPAIR STATION FOR FURTHER INVESTIGATION.