As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFT CARGO THRESHOLD WEB HAS CORROSION. GROUNDED - YES. REMOVED CORROSION FROM WEB SILL. ORIGINAL THICKNESS .045 IAW B737-900 SRM 53-60-15-0I-1. MATERIAL LOSS OF .009. REMAINING IS .036. OUT OF LIMITS IAW B737-900 SRM 53-60-15-1A-1. REMOVED & REPLACED WEB SILL PN: 146A8123U25 PO:1107524.4 IAW BAC DWG 146A8120 REV:A.