As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED A LOUD NOISE ON RT SIDE OF AIRCRAFT AND ELECTED TO RETURN TO CLT LANDING WITHOUT INCIDENT. MAINTENANCE INSPECTED AND FOUND THE OXYGEN SERVICE DOOR LEFT OPEN. MAINTENANCE SECURED THE DOOR CLOSED. AIRCRAFT WAS RELEASED FOR SERVICE. (A)