As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
STL INFLIGHT T720/16AUG DFW TO LGA. CREW REPORTED AFT CARGO FIRE LIGHT ON ANNUNCIATOR. MASTER WARNING ON 1 TO 2 SECONDS THEN EXTINGUISHED. LANDED STL AS PRECAUTIONARY WITHOUT INCIDENT. REPLACED CARGO FIRE MX UNIT AND AFT CARGO SMOKE DETECTORS. SYSTEM GROUND CHECKED NORMAL OPS.