As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CUSTOMER REQUEST: (F.B.) AFT CARGO COMPARTMENT INTERCOSTAL BS 787-807 AT S-27R IS CORRODED. WL 156 / INTERCOSTAL WAS FOUND TO HAVE 100% MATERIAL LOSS. REMOVED AND REPLACED NTERCOSTAL AT STA 787-807 STR 27R IAW BOEING DWG #146A8130 REV: B AND SRM 51-40-02-0G-0. APPLIED CIC TO THE NEW INTERCOSTAL IAW AMM 51-21-91-620-802 PARAGRAPH 3.C. P/N 146A8132-17