I am currently having audio problems on my computer -- so, I do not know what the guy was saying on the video in the OP. However, I imagine that he was making the point that [ even ] "normal fire" can cause iron / steel to become more malleable.
{ If it is heated long enough. }
Okay...
So -- will the fire on one side of the building also melt the same ( similar ) metal structure on the other side of the building ( where there is no fire burning [ at the same level of heat - for the same length of time ] ) -- such that - at a particular moment - the
entire steel structure of the
entire floor ( 360 degrees ) will "break free" and do a 'pancake' free-fall onto the next floor below it?
I think not...
It is
not going to happen unless
all of the metal parts in question are [ essentially ] heated to the
same temperature for the
same length of time -- AND they all "broke free" at the same time...
Otherwise, it would cause the building to topple instead of falling straight down...
At best, the one side would falter while the other side was still holding strong enough to cause the building to lean - and topple - to the side that faltered.
And -- consider the
CORE of each building -- containing multiple ( I have forgotten exactly how many. ) concrete-and-steel
elevator shafts PLUS multiple ( I have forgotten exactly how many. ) LARGE
vertical beams -- both running [ nearly ] the entire height of the building. If the 'pancake' theory were correct and true, then it would have been like dropping donuts down a toilet plunger handle. The
CORE of the building would have remained standing -- rather than being pulverized into dust as the 'pancake' stacking occurs at nearly free-fall speed...
The ONLY way the 'pancake' theory can have any validity at all whatsoever ( falling straight down without
any topple effects ) -- is -- if the outer part of the building fell downward around the CORE of the building -- leaving the CORE standing... ( even if only briefly - before the CORE itself began to topple )
There is NO WAY the entire building is going to disintegrate at nearly free-fall speed in its own footprint ( without toppling ) - "by a purely natural means" -- "without some 'help' from controlled demolition"...