If you look carefully at the pictures, about half way down there is a little black puff.
That can't be anything other than toner. (Laser, toner; I think you might have just solved the mystery Baldimo!).
You're trolling again.
"In videos of the collapse of the North Tower, the upper block is clearly seen dropping down without stopping. You believe that this upper block acted as a pile driver to crush the lower intact core structure below it. But if that were the case, there would have been not only a visible jolt and pause of the downward movement of the upper block, but also the destruction of the more heat-damaged upper block as it met with the lower block. As such, the collapse would have been arrested because the upper block would have been destroyed easier and faster than the intact lower block. But that's not what happened. Once the upper block is in motion, it does not slow down.
"In the case of the South Tower, the upper block tipped over the edge of the building, thereby removing the pile-driver effect which is necessary to your theory. So you claim that some collapsing floors pulled the core and perimeter columns down with them. Of course, you understand that the purpose of the core structure and perimeter columns was to support the floors; not the other way around. Right?"
Go ahead and take a crack at it.