As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
"AWR HIDDEN DAMAGE: AFTER REMOVE INSULATION ON MAIN AVIONICS COMPARTMENT, CORROSION ON INTERCOSTAL AT STGR 20R BTW FS310/364 WAS FOUND IN REF EO: R25120 (SM)[E/E]. "SUMMARY: CORROSION LEVEL 2, INTERCOSTALS AT STGR 20R BTW FS310/364 WERE REPLACED PER CRJ-900 SRM 51-42-06-001-001-A01 AND CRJ-900 SRM 51-42-21-001-001-A01.