As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CORROSION OUT OF LIMITS, SUPPORT FLOOR NEXT TO LOWER SILL AT L4 DOOR WITH ORIGINAL THICKNESS: 0.071 IN AND MINIMUM REMAINING THICKNESS 0.050IN THEREFORE IT IS OUT LIMITS PER B757-300 SRM 53-60-15-1A PROCEDURE 1 ALLOWABLE DAMAGE 1 FIG. 101 DETAIL V. CORROSION LEVEL 2, FLOOR SUPPORT NEXT TO LOWER SILL AT L4 WAS REPLACED PER B757-300 SRM 51-40-02-0G. (1571303) AIRCRAFT WAS GROUNDED