As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
A LOUD EXTERNAL RUMBLE WAS HEARD ACCOMPANIED BY FLASHING GEAR WARNING LIGHTS WHILE CRUISING AT FL 290. THE AIRCRAFT WAS DIVERTED TO BWI WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE FOUND THE NOSE GEAR DOORS OUT OF RIG. THE NOSE GEAR DOORS WERE ADJUSTED IAW MM 32-22-1.