This is a study of the overall downward acceleration of WTC1,
the North Tower of the World Trade Center.
During this investigation it was discovered
that the one feature that kept pace with the original acceleration of the roof-line
was a wave of ejections on the west wall.
A clearer, stabilized view of these ejections
that Chandler is discussing at 5.10 mins in the clip above
can be seen here :
[youtube]NxGJHTlpOc8[/youtube]
.