As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DECLARED EMERGENCY/DIVERSION. AT FL370 ALTITUDE WARNING HORN CAME ON. CABIN ALTITUDE WAS 9500 FT. WENT TO STANDBY ON PRESSURE CONTROLLER, NO HELP. WENT TO MANUAL AND STARTED AN EMERGENCY DESCENT, CABIN GOT TO 11500 FT. NO WARNING LIGHTS. REMOVED AND REPLACED AFT CARGO DOOR SEAL, PER MM.