As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU FIRE WARN IN FLIGHT. COMPLIED WITH QRH. INSPECTED APU COMPARTMENT, NO EVIDENCE OF FIRE OR HEAT DAMAGE. REMOVED AND REPLACED THE APU FIRE BOTTLE ASSY WITH A SERVICEABLE UNIT. OPS CHECK GOOD. P/N: 897889, S/N OFF: 60810EL, P/N: 897776-01, S/N OFF: 01659.