Tower Destruction Timelines
The Explosive Destruction of the Twin Towers, Second-by-Second
Each of the Twin Towers was totally destroyed in a matter of seconds. The score of videos archived here is the basis for a second-by-second timeline of the event.
Timeline Construction Methods
The video timelines are constructed from filmstrips -- columns of video frames extracted from video clips at one-half-second intervals. The filmstrips from a number of different clips are assembled on a page with the vertical axis representing time and the horizontal axis representing angle with respect to the Tower.
The origin of each of the two timelines is chosen to represent the moment of the first motion of any part of the Tower. Those movements are different for the two Towers. The South Tower's top leans for about two seconds before the roof starts to plunge downwards, and the North Tower's radio antenna begins to drop about a half-second before the north side of its roof begins do drop. The rotation of the South Tower's top, and the drop of the North Tower's antenna are used to set the timelines' origins.
Reports of Event Time and Duration
The NIST Report gives the onset of the events as follows:
- South Tower: 09:58:59 AM
- North Tower: 10:28:22 AM
The NIST Report does not give a duration for the events, nor does any other official report except for the 9/11 Commission Report , which states that the South Tower "collapsed in ten seconds." The duration of the destruction of each Tower remains a topic of confusion, based in part on misinterpretations of seismic data. The timelines listed here provide a reasonably accurate account of the progress of each Tower's destruction, and clearly show that each event lasted at least 15 seconds.