As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON CLIMB OUT, HEARD LOUD SQUEAL FROM PAX DOOR AREA. ABOVE 11,000' COULD NOT MAINTAIN CABIN PRESSURE. PACKS NORMAL, DOOR INDICATIONS NORMAL. DIVERTED TO MKE. ***AIRCRAFT REMOVED FROM SERVICE*** R/R PAX DOOR SEAL PER AWA SUP 21-023 AND AMM 52-11-10 OPS AND PRESSURIZATION CHECK GOOD AT THIS TIME.