Visual Evidence, Damage Estimates, and Timeline Analysis. Chapters 1-8. Federal Building and Fire Safety Investigation of the World Trade Center Disaster.
Visual Evidence, Damage Estimates, and Timeline
Analysis. Chapters 1-8. Federal Building and Fire
Safety Investigation of the World Trade Center Disaster.
Pitts, W. M.; Butler, K. M.; Junker, V.
NIST NCSTAR 1-5A; 392 p. September 2005.
World Trade Center; high rise buildings; building
collapse; disasters; fire safety; fire investigations;
terrorists; terrorism; visual evidence; timeline
analysis; damage; impact; aircraft impact; aircraft
speeds; fire behavior; smoke; databases
This report summarizes the collection and analysis of
visual material used for the National Institute of
Standards and Technology (NIST) World Trade Center (WTC)
Investigation. The task consisted of four major
subtasks: 1) identification, collection, data basing,
and cataloging of visual material, 2) timing of material
incorporated into the NIST visual database, 3)
development of fire time lines and additional analyses
based on the visual material, and 4) documentation.
Procedures used for subtasks 1 and 2 are summarized. Two
data bases were assembled containing 6,899 photographs
and 6,977 video clips, with 3,279 of the photographs and
2,772 of the videos timed with 3 second or better
accuracy. The primary output of the task is a series of
Excel data sheets describing individual window
observations (fire, smoke, and whether window is open or
closed) on the four faces of both towers as a function
of time. Fire behaviors are discussed and documented by
a large number of images. Additional analyses include
initial facade damage and fire behavior due to aircraft
impacts, aircraft speeds, and the motion of WTC 2
resulting from the aircraft impact. Unusual fire
behaviors are documented for both towers. Several
hanging objects (possibly floor slabs:) observed inside
WTC 2 and their changes with time are described. Other
observations, including falling victims, falling
streamers, and smoke marks on facade columns, are
documented and related to the observed fire behaviors.