As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FL 380 PRESSURIZATION WARN HORN SOUNDED. RAN CHECKLIST UNABLE TO HOLD PRESS IN MANUAL. EMERGENCY DESCENT - PRESSURIZATION CONTROLLER IN MANUAL WORKED AT 5000 LWR PSI. FOUND APU DUCT REAR BELLOW IN KEEL BEAM CLAMP OFF, RESCUED. PERFORMED CABIN PRESSURE LEAK CHECK, TEST PASS REF AMM 05-51-91-790-80 1.