In order for a building to 'fail' like that (ie symmetrical collapse) every single core column would have to have failed at exactly the same time which is basically impossible. Steel framed buildings normally have massive structural redundancy. They can normally support 2 to 5 times their own weight. When a Steel framed building is rigged for demolition it's very common for them to cut up to 20% of the core columns to weaken the building before it's blown up. These buildings don't magically collapse if a single columns fails as NIST tried to suggest.