The Integrated Surveillance Program, under the Department of Energy, is responsible for the periodic surveillance of storage containers containing plutonium-bearing materials. The container-package consist of a stainless-steel three-layered structure with a convenience can that confines the material, and seal-welded inner and outer cans designed to isolate the materials for up to 50 years with minimal surveillance. The inner-can represents the first layer of material containment, and it should not be breached. During monitoring, corrosion-pitting and suspected stress-corrosion-cracking (SCC) has been identified in some of the inner cans near the weld regions due to the transport of chloride salts and water impurities into the space between the convenience can and the inner can. SCC through wall penetration would result in an undesired increased risk of leakage. An investigation is in progress to identify and characterize corrosion events in the inner-cans to determine the prevalence of corrosion features and the likelihood of a through-wall breach. This document presents a specimen where significant pitting corrosion and cracking was observed in and near the heat affected zone between the can and the lid. Characterization was carried out by Scanning Electron Microscopy (SEM) and 3D-tomography. Tomography was carried out using a Focused Ion Beam (FIB) to mill into the surface of the specimen to map the subsurface topographies of pits and cracks. The study revealed the crack depth and secondary cracks that developed from cracks observed at the surface.