You need to visit
http://www.septemberclues.org and read each page. After September Clues showed evidence of CGI planes, the team here then showed evidence of CGI buildings CGI witnesses and CGI victims. So yeah, a lot of your questions will be answered, when you read up there at the link posted, and here, most especially in the stickied "pinned" threads at the top of each sub-forum heading.
When you actually look at the evidence of image forgeries, you'll realize you've been wasting the past 13+ years analyzing an entirely fake 101-minute computer graphic image compilation, animated to appear like actual videos were taken that day.
The perfectly normal (yet totally illegal, because of the asbestos problem) controlled demolition was not broadcast, so again, you've been (like the majority of humanity) analyzing forged "footage" (and not noticing it was forged, which yes is quite embarrassing.)
I looked at the "projectile video" a thousand times, with this obviously brightly lit-up north-face in the background, without EVER noticing until now that it was pointed out here at
http://www.CluesForum.info that the North Face should in reality NEVER have been depicted as brightly lit up by the sun!
The North Face in reality, of both towers, should always be in the shade. The "divebomber video" even shows the north face as being in the shade. So why does the "projectile video" show the north face being brightly lit up by the sun, an occurrence which in reality has never happened even once in history? The answer is: because the buildings are CGI bro, just like the planes are CGI. Deal with it. The whole 101 minutes. Not one moment of actual footage in it.
You were analyzing a cover-up, a fictional movie, which masqueraded as "news footage" and "amateur footage".
You have seen no actual footage of what happened on 9-11 at WTC. Nobody has. It was totally smoke-machined out of view. Period.
So arguing about whether or not they threw some extra little piece of metal or two at the buildings before starting up the smoke machines, after having evacuated the area of course, before the normal controlled demolition (cleaned up by a company quite properly called Controlled Demolition, inc) is moot really.
Admit it all was CGI first, and then come back and tell us if we still need to be divisively arguing about little demolition details.
Enjoy the reading, and then come back with proper unity in the understanding of reality: the "News Footage Videos" and "Amateur Footage Videos" were in fact all CGI creations, brother!