As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIR TURN BACK AT KOA STATION DUE LOUD BANG, ENGINE SHUTDOWN, TGT 1149.5 DEGREES. PERFORMED CHECK LIST AND FIRED 1 FIRE BOTTLE. RETURN TO AIRPORT. REMOVED NR 1 ENGINE PER M144-717 REF LG PG 216722/75. INSTALLED NR 1 ENG PER HALM 143-717 GROUND RUNUP & LEAK CHECK OKAY.