As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DFW - INFLIGHT HAD APU FIRE DETECTION SYSTEM ALARM. BOTH FIRE BOTTLES ACTIVATED AND USED. LANDED DFW WITHOUT INCIDENT. FOUND RUBBER BOOT ON SURGE CONTROL VALVE LEAKING ONTO FIRE LOOP. TIGHTENED BOOT AND REPLACED BOTH FIRE BOTTLES. SYSTEM GROUND CHECKED NORMAL OPERATION.