TEXT: The Last Column is a 58-ton, 36-foot-tall piece of plated steel that was part of the core structure of the World Trade Center's South Tower. It became a makeshift memorial when police, firefighters and other emergency personnel left messages honoring their fallen co-workers. The column is adorned with names, organization stickers, photos, uniform patches and posters.The Last Column is so-named because it was the last- tanding piece of steel during the Ground Zero cleanup. It was stored at Kennedy Airport until 2009 when it was installed in the museum's Foundation Hall. The museum opened May 2014. The slurry wall, to the right, was part of the WTC's foundation. Built to hold back the waters of the Hudson River, it made construction of the towers possible.