As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
TAIL COMPARTMENT HIGH MSG FL 180 AND CLIMBING. FOLLOWED QRH LIGHT EXTINGUISHED AND THEN CAME BACK ON. DURING DESCENT TO ATL LIGHT STAYED EXTINGUISHED. MTC IS PROGRESS DNTC. FOUND DUCT ASSY BLOWN REF: 21-20-00-04 ITEM 385 MFG NR 5924037-513 DUCT ASSY (HEADER).