What I mean is that you wouldnt be able to just go around and mount so many devices with wires and fuses using some unknown substance able to cut so many steel beams so fast, while steel melts at 1.2k Celsius and only titanium is stronger. Even if you had the building closed for a year, you would still doubt your calculations to achieve what you saw with your own eyes, right?

This video does not prove anything: youtube.com/watch?v=5d5…

You can see how he mounts this (7:50)? When would anyone be able do mount so many devices without notice in steel beams of the core of the building? Not possible. More importantly, you wouldn't be sure that the outcome would be so remarkably precise demolishion. That is why it was not possible. It was impossible unless.... Any hint from you? :)