UPDATE: Video now available on the NIST website. See the frame with NE corner flash at initiation. Still images from this video appear in NIST volume 1-6, for both the North and South Tower events. One televised version comes from the 2002 History Channel documentary “World Trade Center: Rise and Fall of an American Icon” at vrt 00:06:46. A similar angle is NBC view 3, with the Woolworth Building at center.
As the “collapse” initiates, watch the flash in the NE corner about 10 stories (?) above the plane engine’s exit hole. The top section of the tower soon begins to crumble at that explosion point– revealing part of the effort to prevent the top of the building from crashing by itself into the street.
Raw NIST FOIA file: Onno deJong Clip_6 (Now on the NIST website in full – agree to terms then re-click this link.)
Onno de Jong
YouTube 1 & 2
