As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 654 - CLT-ROA - ON CLIMB-OUT, THE APU FIRE WARNING LIGHT CAME ON AND BELL SOUNDED. CAPTAIN FIRED ONE BOTTLE. THE LIGHT DID NOT EXTINGUISH. EMERGENCY WAS DECLARED. FLIGHT RETURNED AND LANDED CLT WITHOUT FURTHER INCIDENT. MAINTENANCE REPLACED THE FIRE SENSING ELEMENTS AND FIRE BOTTLE. REFERENCE USAAF97034.