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 and killing 184. Now, decades post 9/11, Americans and foreign visitors go to Washington D.C. to remember and honor heroes at the National Pentagon 9/11 Memorial. But this isn’t just any stone memorial. There’s an impressive explanation and reason for the Pentagon Memorial’s design.