As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: DURING CLIMB ABOVE FL150, PILOTS NOTICED THE CABIN ALTITUDE CONTINUING TO CLIMB PAST 9500FT. CABIN ALTITUDE REACHED 12600FT. PILOTS FOLLOWED THE CABIN ALTITUDE PROCEDURE AND RETURNED TO LAND. MASKS WERE DEPLOYED. (OPEN)