CarolC

I challenge you to prove that Minoru Yamasaki (archtitect of the TWC towers) supports your claims about the structural load-bearing inolvement of the cores. Because I know how the building was designed to stand and I know that you cannot prove that comment, because it is wrong. Sorry, Carol, it' just that simple.

The angle braces that hold the floor trusses to the core structure are the weakest links - the ones involved in the fire failed. That started the collapse. The weight of the collapsing upper section overwhelmed everything below it, a combination of the falling debris and the undamaged floor slabs tearing away at the fabric of the core structure, explains everything that you see in all the photos and videos of the collapses.

CarolC - do you seriously imagine that the core structure has any independent strength? You say that the core should have stood independently. Do you really believe that? That a 400m concrete column can stand on its own?