As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING C-CHECK LAVATORY UNDER FLOOR OMEGA BEAM CAP IS CORRODED AS MARKED ON LT SIDE AROUND NUT PLATE. MAINTENANCE DETERMINED CORROSION ON OMEGA BEAM CAP LT SIDE FRAMES 59-61 IS 100 PERCENT MATERIAL LOSS IAW SRM 53-24-10. MAINTENANCE R & R LT GUSSET IAW SRM 51-40-02. THE ACFT WAS APPROVED FOR RETURN TO SERVICE.