As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFT CABIN FLOOR STRUCTURE L/H INTERCOSTAL STA967- STA947.5 CORRODED ON MULTIPLE LOCATIONS. REMOVED AND REPLACED L/H INTERCOSTAL AT AFT MAIN CABIN FLOOR STRUCTURE AREA BETWEEN STA967 TO STA 947.5 AS PER REF B737-900 SRM 51-50-02. (LOG 1637792 - AIRCRAFT WAS GROUNDED).