Workers walk by the World Trade Center south tower excavation display at the National Sept. 11 Memorial Museum, Wednesday, May 14, 2014, in New York. The museum is a monument to how the Sept. 11 terror attacks shaped history, from its heart-wrenching artifacts to the underground space that houses them amid the remnants of the fallen twin towers’ foundations. It also reflects the complexity of crafting a public understanding of the terrorist attacks and reconceiving ground zero. (AP Photo)