As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 5584, IAH TO MOB - ON CLIMB OUT OF IAH THE FLIGHT CREW RECEIVED A LEFT 14TH STAGE DUCT LEAK WARNING. THE QRH WAS FOLLOWED AND THE AIRCRAFT RETURNED TO IAH AND LANDED WITHOUT INCIDENT. MAINTENANCE INSPECTED THE 14TH STAGE DUCTING AND FOUND THE HEAT SHIELD ON THE LEFT 14TH STAGE DUCT BURNED. THE DUCT WAS REPLACED BUT THE DUCT LEAK MESSAGE RETURNED DURING THE OPS CHECK. THE 14TH STAGE DETECTOR LOOP WAS THEN FOUND TO BE THE CAUSE AND WAS REPLACED.