As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT FL 280 A LOUD POP COULD BE HEARD FROM WHAT SOUNDED LIKE THE MAIN CABIN DOOR. DID NOT STOP UNTIL WE LANDED / REINSTALLED THE PASSENGER DOOR SEAL IAW CRJ700 AMM 52-11-07-400-801-A02. LEAK CHECK GOOD AT THIS TIME AND NO MORE SQUEALING NOISE NOTED AT THIS TIME."