As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PIT - FLT 474 - ON CLIMB-OUT FROM PIT, AT 8,000 FEET, THE AIRCRAFT WOULD NOT PRESSURIZE. FLIGHT RETURNED TO FIELD AT PIT AND LANDED WITHOUT FURTHER INCIDENT. NO EMERGENCY WAS DECLARED. MAINTENANCE DETERMINED THAT CATERING DID NOT PROPERLY CLOSE THE AFT LEFT ENTRY DOOR. CHECKED OPERATION AND LATHCES OF DOOR. FOUND OK. CHECKED LIGHT OPERATION OF DOOR. FOUND NORMAL. AIRCRAFT OK FOR SERVICE. (M)