- Author
-
Grosshandler, W. L.
- Title
- Fire-Induced Collapse of World Trade Center 7: Results of the NIST Building and Fire Safety Investigation of the World Trade Center Disaster.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD
- Book or Conf
- Fire Science and Fire Protection Engineering, 2009 International Symposium. Proceedings. China Fire Proection Association. October 2009,
Beijing, China,
Jinhua, S.; Jie, J., Editors,
1-17 p.,
2009
- Keywords
-
fire science
|
fire protection engineering
|
fire protection
|
World TradeCenter
|
fire safety
|
fire investigations
|
disasters
|
high rise buildings
|
office buildings
|
building collapse
|
reconstruction
|
occupants
|
evacuation
|
computer simulation
- Abstract
- This paper provides a summary of the final report of the National Institute of Standards and Technology (NIST) investigation into the collapse of WTC 7, conducted under the National Construction Safety Team Act. The report is the result of an extensive, state-of-the-art reconstruction of the events that affected WTC 7 and eventually led to its collapse. Numerous facts and data were obtained, then combined with validated computer modeling to produce an account that captures the key features of what actually occurred. However, the reader should keep in mind that the building and the records kept within it were destroyed, and the remains of all the WTC buildings were disposed of before congressional action and funding was available for this Investigation to begin. As a result, there are some facts that could not be discerned and, thus, there are uncertainties in this accounting. Nonetheless, NIST was able to gather sufficient evidence and documentation to conduct a full investigation upon which to reach firm findings and recommendations. INTRODUCTION: World Trade Center 7 (WTC 7) was a 47 story office building located immediately to the north of the main WTC Complex in New York City. It had been built on top of an existing Consolidated Edison of New York (Con Edison) electric power substation, which was located on land owned by The Port Authority of New York and New Jersey (PANYNJ). On September 11, 2001, WTC 7 endured fires for almost seven hours, from the time of the collapse of the north WTC tower (WTC 1) at 10:28:22 a.m. until 5:20:52 p.m., when WTC 7 collapsed. This was the first known instance of the total collapse of a tall building3 primarily due to fires. WTC 7 was unlike the WTC towers in many respects. It was a more typical tall building in the design of its structural system. It was not struck by an airplane. The fires in WTC 7 were quite different from those in the towers. Since WTC 7 was not doused with tens of thousands of liters of jet fuel, large areas of any floor were not ignited simultaneously. Instead, the fires in WTC 7 were similar to those that have occurred in several tall buildings where the automatic sprinklers did not function or were not present. These other buildings did not collapse, while WTC 7 succumbed to its fires. This paper provides a summary of the final report of the National Institute of Standards and Technology (NIST) investigation into the collapse of WTC 7, conducted under the National Construction Safety Team Act. The report is the result of an extensive, state-of-the-art reconstruction of the events that affected WTC 7 and eventually led to its collapse. Numerous facts and data were obtained, then combined with validated computer modeling to produce an account that captures the key features of what actually occurred. However, the reader should keep in mind that the building and the records kept within it were destroyed, and the remains of all the WTC buildings were disposed of before congressional action and funding was available for this Investigation to begin. As a result, there are some facts that could not be discerned and, thus, there are uncertainties in this accounting. Nonetheless, NIST was able to gather sufficient evidence and documentation to conduct a full investigation upon which to reach firm findings and recommendations.