As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT'S DOOR POPPED OPEN IN FLIGHT, PILOT DIVERTED TO THE NEAREST AIRPORT, LANDED AND RE-LATCHED THE DOOR. THEN CONTINUED ON TO DESTINATION. ONCE THERE, THE UPPER DOOR LATCH CHANNEL (AIRFRAME SIDE) WAS FOUND TO BE LOOSE AND WAS TIGHTENED AND RETURNED TO SERVICE.