As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU FIRE WARNING ON APPROACH. APU WAS NOT OPERATING AND WAS CURRENTLY ON MEL 49-01 DMI 737-08-20. CAPTAIN'S AFTER LANDING INSPECTION FOUND NO EVIDENCE OF FIRE OR/OVERHEAT. PILOTS FOLLOWED AFM PROCEDURES AND FIRED APU FIRE EXTINGUISHER BOTTLE.