What's hiding behind the Bushes?

Big ceremony today in Texas, unveiling a statue of Bush Sr. and Bush Jr.   News item also mentioned a 9-11 museum piece made from a "part of the second tower that collapsed." Why doesn't this museum have a piece of the third tower that collapsed? You know, the one that dozens of Youtube videos show, but absolutely no one in Washington ever talks about? Not talking conspiracy theory here at all. There's nothing theoretical about the footage of that third building collapsing without being hit by anything.