As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFT CARGO TRANSITION PANEL AT LBL-21 HAS MULTIPLE AREAS OF CORROSION BETWEEN STA 727+4 TO STA 847. GROUNDED - YES. REMOVED CORROSION, FOUND TO BE OUT OF LIMITS IAW B737-800 SRM 53-00-53-1A-2 REMOVED AND REPLACED TRANSITION IAW BOEING 737-800 SRM 53-00-53-2R-5W= 1.00 O= .040 R= .033 L= 4.25 D= .007.