The National 9/11 Memorial at Ground ZeroStarting in the summer of 2005, members of the AEF Team began to work on what may be the most important project since we opened for business in 1964. Before the first meeting, non-disclosure agreements had to be signed. We were not even permitted to disclose the name of the project to anyone outside our team. On our internal servers, the project folder was -- and still is -- labeled "Courtyard Waterfall". In actuality, the project was the National 9/11 Memorial at Ground Zero, and we would be working on it for the next seven years.