As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS FLYING AT FL39, HEARD AN AIR NOISE NEAR THE CABIN DOOR. STARTED TO LOOSE PRESSURIZATION. DECLARED AN EMERGENCY AND DESCENDED TO A SAFE ALTITUDE. DIVERTED TO LIT AND LANDED WITHOUT INCIDENT. MX DETERMINED THE CABIN DOOR SEAL WAS BAD AND REPLACED WITH NEW, THE AIRCRAFT WAS TEST FLOWN AND FOUND TO BE OK.