As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: AN EMERGENCY WAS DECLARED DUE TO: SHORTLY AFTER LEVEL OFF AT FL370, CABIN ALTITUDE ALERT SOUNDED AND FLASHED, MANUALLY DEPLOYED MASKS. AIRCRAFT DIVERTED TO AND LANDED SAFELY AT PIT. GVI OF APU AIR DUCT BOOT. REMOVED AND REPLACED OUTFLOW VALVE (AALA202512088232). ALSO REMOVE AND REPLACED BOTH POSITIVE PRESSURE RELIEF VALVES (AALA202512164641), (AALA202512165396).