As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAH - FLIGHT 4211, THE CREW REPORTED THAT ON CLIMB THE CARGO BAY FILLED WITH SMOKE AND PRESSURIZATION WAS LOST. THE AIRCRAFT RETURNED TO IAH WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE INSPECTED THE AIRCRAFT AND FOUND THE NUMBER ONE ENGINE PNEUMATIC DUCT CLAMP IN THE CARGO BAY TO HAVE COME APART. MAINTENANCE REPLACED THE AFFECTED CLAMP, AND THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.