I’m sorry they did not include the report/documentary, done by the architect that designed the twin towers , he was really driven to know how the towers could come down like that, any ways he and his own team did their own research and showed all the computer models they came up with as they did their research, and came up with a computer model that found that most of the foam insulation on all the steal would have been blown away by the planes and the fire ,so that that outer shell of steal that the interior floor trusses hung from must have twisted and been pushed outward so that the floors just began to drop straight down onto each floor below , there was so much weight above the floors that began to fail that nothing could stop the domino effect .like free fall. I wish I knew a link to the video on YouTube so everyone can see the computer recreation,