Some Demolitions gone wrong. These are typically trained professionals who's best efforts didn't produce the desired result, and the demolitions lead to collapses which in many cases took place WELL outside of their 'footprints'. Obviously demolition, even when carried out by professionals, doesn't always lead to a full collapse, nor does it always result in contained debris. On 9/11 you have 3 skyscrapers which went through full and complete collapse apparently with no professional help whatsoever, due to the impacts of two planes. Whatever arguments you might make about what consists of 'their own footprint', there's no question the buildings were completely and rapidly leveled, and in none of the three collapses was there any leaning, tilting, sliding, or any 'off-center' aspects to their destruction. All three came down top-to-bottom swiftly and fluidly, and more-or-less straight down. Do these collapses, individually, have all the hallmarks of controlled demolition? No. Are there indications of demolitions of some sort taking place? Yes. Otherwise demolition experts wouldn't be identifying building 7 as a demolition before they know the building collapse they're watching was part of the WTC. The man being interviewed is dead now, crashed his car into a tree a couple of years back.