As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU FIRE WARNING BELL AND LIGHT ILLUMINATED DURING FLIGHT. PULLED FIRE HANDLE AND DISCHARGED APU FIRE BOTTLE. INSPECTED APU AND TAILPIPE, NO EVIDENCE OF FIRE FOUND. OK TO CONTINUE PER MEL. REMOVED AND REPLACED FIRE BOTTLE DURING OVERNIGHT CHECK PER MM.