As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MIA - CREW REPORTED PRESSURIZATION PROBLEM DUE TO LEFT PACK AND BLEED FAIL. FLIGHT ATTENDANT STATED, HEARD A LOUD POP BY THE RIGHT NUMBER 1 DOOR FOLLOWED BY A LOUD SQUEAL. THE O2 MASKS WERE DEPLOYED. EMERGENCY DECLARED FLIGHT RETURNED MIA LANDED WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. REPLACED LEFT CONTROLLER. SYSTEM GROUND CHECK NORMAL OPERATION.