While your photo seems to be a little overkill I think you might be on to something. To show our resolve and intent to continue on etc. We should rebuild the WTC, with appropriate memorialization of course, and instead of building 2 towers we should build 4. Sort of a symbolic statement of you only make us stronger. Or that recurring theme in horror movies where they cut the beast apart and all the pieces regenerate a new beast. Disney's Sorcerers Apprentice with Mickey Mouse from the film Fantasia comes to mind. Mickey smashes the broom into splinters and each splinter generates a new broom. Before he knows it he is trying to fight off hundreds of brooms.