As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT, LT REAR PASSENGER DOOR POPPED OPEN IN FLIGHT AC LANDED ON SS154 THE DOOR WAS SHUT AND SECURED. AFTER TAKE OFF THE DOOR POPPED OPEN AGAIN AIRCRAFT LANDED. THE MECHANIC FOUND A 3 INCH CRACK ABOVE THE LOWER LATCH. THE DOOR WAS REMOVED AND REPLACED.