The perimeter section seen above stood intact just beside the NE corner of WTC2 well after the entire upper part of the building disappeared from view.
The original location of the top of the piece was within one floor of and just under where a molten substance was witnessed to pour out of the building in the time leading up to the collapse as this presentation will show.
The spandrel breaks along the left side of the section occur just along the NE corner, along the bolt connections between the prefabricated corner section and the cornermost prefabricated 3 column by 3 spandral perimeter section on the north face.
Here is an extreme close-up of the fold-in of the NE corner:
The surviving corner shown was just below this failure point.
To locate the height of the top of the piece, we use a video clip in which the camera is stationary using the high resolution of the source video here , frames 5960 to 6400.
The next image is frame 6262 in which I make a red mark at the top of the piece in question.
Amazing that the piece could survive intact at all at that location.
By frame 2015, shown above, the surviving section is still standing in place. It has not yet begun to move downwards and is therefore supported from below by an intact wall that must exist within the dust.
The very top of the upper section of the falling building has already fallen well below this elevation by this time.
We also know that the east wall has already fallen considerably by this time, peeling away from the building as a single interconnected intact sheet broken along the NE and SE corners.
Of interest is that the piece is only the top of what must be a much larger intact wall.
The spandrel breaks on the left, just along the corner of the building, are also of interest as future presentations will show. These spandrel breaks occur along a straight vertical line, only the topmost of which are visible within the image. But the pattern of breaks must continue down a vertical line within the dust.
Why? Because the wall remains standing, yet we know the entire east face peeled away as a single sheet broken at both it's corners, the entire sheet being easily identifiable within the rubble.
Below. 3 frames from a video in which the camera is stationary confirms that the perimeter section that remained stading was from just below the initial failure point.
We place frame 5964 (taken before the building started to fall) over the image above.
We show where the red mark is relative to the standing building in the next image.
We can see the top of the piece is at the bottom of where the NE corner has become blackened due to fire.
The next series of images of is from the same source video, frames 1720 to 2100. Using what we've learned I estimate where the outline of the piece is using the soot marks along the NE corner.
The reader can see it is within one floor of where the molten substance was seen leaving the building and where the corner was originally seen to kink.
A mechanism of stripping the NE corner from the rest of the building can be seen below:
The upper NE corner moves inside the lower, stripping the lower of flooring.
Created on 06/09/2009 10:39 PM by admin
Updated on 04/27/2011 01:18 AM by admin
