Americans will never forget the tragedy of September 11, 2001. During the attacks on the United States, terrorists overcame the crew of Flight 77; thus attacking the military defense hub of the United States killing 184. Now, decades later, Americans and foreign visitors go to Washington D.C. to remember and honor them by visiting the 9/11 Pentagon Memorial. But this isn’t just any stone memorial. There’s an impressive explanation and reason for the Pentagon Memorial’s design.