As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON FINAL APPROACH TO RDU, STARTED APU AND WHILE IN START CYCLE APU FIRE WARNING CAME ON. DISCHARGED FIRE BOTTLE. INSPECTION OF APU ENCLOSURE AND APU AREA REVEALING NO EVIDENCE OF FIRE. ASSIGNED DMI NR 05336 PER MEL 49-00-1 APU INOP. NO OPERATION ALLOWED.