As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFT CARGO DOOR THRESHOLD HAS CORROSION ON TOP SURFACE THROUGHOUT. GROUNDED - YES. REMOVED CORROSION AND EVALUATED AFT PIT DOOR THRESHOLD IAW B737-900 SRM 53-60-15-1A-1 . ORIGINAL THICKNESS .045 . MAT REMOVED .006 . FOUND TO BE OUT OF LIMITS IAW B737-900 53-60-15-05-1. REMOVED AND REPLACED DOOR THRESHOLD IAW B737-900 DWG # 146A8120-REV-A AND B737-900 SRM 51-40-02.