Curioso #3: There is evidence that the east facade of WTC 2 from the 80th floor downwards fell as an interconnected single sheet of unbuckled perimeter column sections. The spandrel plate connections and column-to-column bolt connections remained largely intact until far into it's fall or upon hitting the ground.
Proof:
In the following photo please notice the location of the mechanical room relative to floor 81 where the inward belding will form.
The mechanical room has noticably higher ceilings than the other floors both above and below.
I believe I have located where a number of perimeter columns of this mechanical room were found in the rubble, shown below.
These perimeter columns are clearly speared into the earth.
They were pushed outwards and fell close to 80 floors. They were then speared into the earth with obvious extreme force.
Despite this, they held up well and exhibit no noticable buckling along their lengths.
As odd as that may seem, it is the location at which they were found that is even more surprising.
The following 2 photos will help us identify their location.
These columns were located on the edge of the street on the other side of WTC 4.
They were some of the farthest columns spotted in that direction.
Lets look at a map of the complex.
These columns cleared the entire WTC 4 building and ended up speared into the ground on the edge of the street.
The following video clip shows a large sheet of intact perimeter columns seen falling away from the building after the "upper block" had escaped view.
http://www.youtube.com/watch?v=nLHGLI1Ihv0
Please note the visible perimeter sheet at 0:17 of this 0:21 second clip.
This sheet is the intact perimeter columns of the LOWER BLOCK falling outwards. It is not in freefall. It is being pushed outwards just as if it is just the top of an intact sheet peeling away from the building.
It is easy to see that the top columns are from the 78, 80th floor area. Therefore we expect to find (and do find) the tops of these columns among the farthest displaced debris directly to the east.
Once again, no collective buckling seen among the members of this sheet as they are seen in the rubble. The single sheet peeling away means that perimeter connections largely survived the initial peeling process.
The connections seemed to "fail" just along the collapse initiation area and along the 2 edges of the east facade, hence the single sheet.
