As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE LBL 24 LONGITUDINAL FLOORBEAM OVER THE CENTER WING WAS FOUND WITH A CRACK IN THE BEAM WEB DOUBLER AT FS 678. THE CRACKED WEB DOUBLER WAS REMOVED. A NEW WEB DOUBLER WAS INSTALLED AND THE BEAM MODIFIED PER BAC S/B 737-57-1139. THE REPAIR WAS ACCOMPLISHED PER ER/A 380725-14, REV A.