As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING INSPECTION, CORROSION WAS FOUND ON FRAME 39 AT BL 0 REQUIRING A FRAME REPAIR. THE CORROSION ORIGINATED FROM A BLUE WATER SPILL AT SOMETIME IN THE PAST. THE LAV WAS PREVIOUSLY REMOVED DURING A RECONFIGURATION OF THE A/C. THIS IS AN ISOLATED CASE AND HAS NOT BEEN FOUND ON OTHER A/C IN OUR FLEET. REPAIR REF: ATR 72 SRM 53-61-40 FIG 110 SHEET 1.