There are 184 memorial units. Each unit is dedicated to an individual victim, where it is placed depends on many things. Some of the many things is age. The youngest was Dana Falkenberg, 3 years old, and the oldest John D. Yamnicky, age 71. While each memorial unit locates itself on its age line, the units are next organized by birthday along the age line. The gap between ages is very evident. Next, the units are organized by depending on whether the victim was on board the airplane or in killed in the Pentagon. If the victim was on the airplane their name is engraved into the side of the unit with the sky and if the victim was in the Pentagon their name is engraved and then the Pentagon in the same view.