Final Reports of the Federal Building and Fire
Investigation of the World Trade Center Disaster
NIST NCSTAR 1: Federal Building and Fire Safety Investigation of the
World Trade Center Disaster: Final Report of the National Construction
Safety Team on the Collapses of the World Trade Center Tower
This is the final report on the National Institute of Standards and
Technology (NIST) investigation of the collapse of the World Trade Center (WTC)
towers, conducted under the National Construction Safety Team Act. This
report describes how the aircraft impacts and subsequent fires led to the
collapse of the towers after terrorists flew jet fuel laden commercial
airliners into the buildings; whether the fatalities were low or high,
including an evaluation of the building evacuation and emergency response
procedures; what procedures and practices were used in the design,
construction, operation, and maintenance of the towers; and areas in current
building and fire codes, standards, and practices that warrant revision.
Extensive details are found in the 42 companion reports. (The final
report on the collapse of WTC 7 will appear in a separate report.)
Also in this report is a description of how NIST reached its conclusions.
NIST complemented in-house expertise with private sector technical experts;
accumulated copious documents, photographs, and videos of the disaster;
established baseline performance of the WTC towers; performed computer
simulations of the behavior of each tower on September 11, 2001; combined
the knowledge gained into a probable collapse sequence for each tower;
conducted nearly 1,200 first-person interviews of building occupants and
emergency responders; and analyzed the evacuation and emergency response
operations in the two high-rise buildings.
The report concludes with a list of 30 recommendations for action in the
areas of increased structural integrity, enhanced fire endurance of
structures, new methods for fire resistant design of structures, enhanced
active fire protection, improved building evacuation, improved emergency
response, improved procedures and practices, and education and training.
NIST NCSTAR 1: Federal
Building and Fire Safety Investigation of the World Trade Center Disaster:
Final Report of the National Construction Safety Team on the Collapses of
the World Trade Center Tower
Companion Reports: NCSTAR 1-1 through NCSTAR 1-8
NIST NCSTAR 1-1: Design,
Construction, and Maintenance of Structural and Life Safety Systems
NIST NCSTAR 1-2: Baseline
Structural Performance and Aircraft Impact Damage Analysis of the World
Trade Center Towers
NIST NCSTAR 1-3: Mechanical
and Metallurgical Analysis of Structural Steel
NIST NCSTAR 1-4: Active
Fire Protection Systems
NIST NCSTAR 1-5: Reconstruction
of the Fires in the World Trade Center Towers
NIST NCSTAR 1-6: Structural
Fire Response and Probable Collapse Sequence of the World Trade Center
Towers
NIST NCSTAR 1-7: Occupant
Behavior, Egress, and Emergency Communication
NIST NCSTAR 1-8: The
Emergency Response Operations
(For a printed copy of NIST-NCSTAR 1, contact
NIST at inquiries@nist.gov.
Also available are CD sets containing all of the reports, from the National Technical Information
Service (NTIS), http://www.ntis.gov
or 800-553-6847.
NTIS order
number: PB2006-100819)
