As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IT WAS REPORTED THAT DURING FLIGHT DL89 (14JAN2020), THE AIRCRAFT N860DA #2 ENGINE (S/N:51201) SUFFERED SURGE & HIGH N3 VIBRATION DURING CLIMB. CREW ELECTED AIR TURN BACK AND THE ENGINE WAS SENT TO HAESL FOR INVESTIGATION. UPON DISASSEMBLY, 1-OFF HPT BLADE WAS PARTIALLY RELEASED (BROKEN APPROXIMATELY AT THE MID-HEIGHT) WHICH SUBSEQUENTLY CAUSED IMPACT DAMAGE TO THE DOWNSTREAM TURBINE BLADES AND NGVS. THE BLADE WAS SENT TO RR LABORATORY FOR FURTHER INVESTIGATION.