As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 6816 - LGA-BOS - AFTER TAKEOFF, AIRCRAFT LOST PRESSURIZATION. FLIGHT ATTENDANT REPORTED LOUD NOISE FROM R-1 DOOR. RETURNED TO AIRPORT FOR LANDING. FOUND R-1 DOOR NOT CLOSED. UPPER FORWARD CORNER NOT IN ROLLER. OPENED AND CLOSED DOOR. OPERATION CHECKED NORMAL. LIGHT EXTINGUISHED PER MM 52-12-0. (M)