As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PRIOR TO TIME OF DESCENT, APU FIRE WARNING. ACCOMPLISHED EMERGENCY PROCEDURES. BOTTLED DISCHARGED. LIGHT REMAINED ILLUMINATED. INSPECTED APU EXHAUST AND APU COMPARTMENT FOR DAMAGE OR EVIDENCE OF FIRE, NONE FOUND. APU WAS NOT RUNNING AT TIME OF FIRE WARNING. SUSPECT DETECTION SYSTEM FAULT.