As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE OPERATING AND CLOSING MAIN CABIN DOOR THERE WAS A SOUND OF LOOSE MATERIAL SLIDING WITHIN THE DOOR. MX REMOVED THE OUTER PART OF THE MAIN CABIN DOOR AND FOUND A NR OF BROKEN RIVETS BETWEEN THE OUTER AND INNER LAYERS. MX R & R THE RIVETS IAW AMM AND OPS CHECKED GOOD.