Featured Research

from universities, journals, and other organizations

Latest Findings From NIST World Trade Center Investigation Released

Date:
April 11, 2005
Source:
National Institute Of Standards And Technology
Summary:
The Commerce Department’s National Institute of Standards and Technology (NIST) presented its analysis of how the World Trade Center (WTC) towers collapsed after two aircraft were flown into the buildings by terrorists on Sept. 11, 2001. This is the most detailed examination of a building failure ever conducted.

NEW YORK CITY (April 5, 2005) -- The Commerce Department’s National Institute of Standards and Technology (NIST) today presented its analysis of how the World Trade Center (WTC) towers collapsed after two aircraft were flown into the buildings by terrorists on Sept. 11, 2001. This is the most detailed examination of a building failure ever conducted.

Related Articles


“Like most building collapses, these events were the result of a combination of factors,” said Shyam Sunder, lead investigator for the agency’s building and fire safety investigation into the WTC disaster. “While the buildings were able to withstand the initial impact of the aircraft, the resulting fires that spread through the towers weakened support columns and floors that had fireproofing dislodged by the impacts. This eventually led to collapse as the perimeter columns were pulled inward by the sagging floors and buckled.”

The probable collapse sequences, which update and finalize hypotheses released by NIST last October, were presented by Sunder at a press briefing in New York City.

The specific factors in the collapse sequences relevant to both towers (the sequences vary in detail for WTC 1 and WTC 2) are:

* Each aircraft severed perimeter columns, damaged interior core columns and knocked off fireproofing from steel as the planes penetrated the buildings. The weight carried by the severed columns was distributed to other columns. * Subsequently, fires began that were initiated by the aircraft’s jet fuel but were fed for the most part by the building contents and the air supply resulting from breached walls and fire-induced window breakage. * These fires, in combination with the dislodged fireproofing, were responsible for a chain of events in which the building core weakened and began losing its ability to carry loads. * The floors weakened and sagged from the fires, pulling inward on the perimeter columns. * Floor sagging and exposure to high temperatures caused the perimeter columns to bow inward and buckle—a process that spread across the faces of the buildings. * Collapse then ensued.

The sequences are supported by extensive computer modeling and the evidence held by NIST, including photographs and videos, recovered steel, eyewitness accounts and emergency communication records. Additionally, this information was used to document a variety of factors affecting the performance of the buildings, the efforts of emergency responders and the ability of occupants to escape prior to the collapses. In turn, NIST has identified a number of future practices and technologies that potentially could have enhanced building performance and life safety capabilities on 9-11 had they been available for implementation. All are being considered for NIST’s upcoming recommendations.

NIST also released drafts of 15 reports from three projects of the investigation: analysis of building and fire codes and practices; occupant behavior, egress and emergency communications; and fire service technologies and guidelines.

Recommendations for improvements to building and fire codes, standards and practices derived from these and the other five projects in the investigation will be released for public comment in June, along with the draft of the final investigation report and drafts of 27 reports from the remaining five projects.

The NIST WTC investigation’s goal is to recommend improvements in the way people design, construct, maintain and use buildings, especially high-rises.

Accompanying this release are selected portions of Sunder’s presentation at today’s press briefing that detail the findings on structural and life safety factors, and the future technologies/practices by which these factors might have been enhanced on 9-11 had they been available. Sunder’s full presentation (including the complete probable collapse sequences for both WTC towers), the text of the 15 reports issued, and all previous WTC investigation findings are available at http://wtc.nist.gov.

###

As a non-regulatory agency of the U.S. Department of Commerce’s Technology Administration, NIST develops and promotes measurement, standards and technology to enhance productivity, facilitate trade and improve the quality of life.


Story Source:

The above story is based on materials provided by National Institute Of Standards And Technology. Note: Materials may be edited for content and length.


Cite This Page:

National Institute Of Standards And Technology. "Latest Findings From NIST World Trade Center Investigation Released." ScienceDaily. ScienceDaily, 11 April 2005. <www.sciencedaily.com/releases/2005/04/050411122017.htm>.
National Institute Of Standards And Technology. (2005, April 11). Latest Findings From NIST World Trade Center Investigation Released. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2005/04/050411122017.htm
National Institute Of Standards And Technology. "Latest Findings From NIST World Trade Center Investigation Released." ScienceDaily. www.sciencedaily.com/releases/2005/04/050411122017.htm (accessed October 25, 2014).

Share This



More Matter & Energy News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

IKEA Desk Converts From Standing to Sitting With One Button

IKEA Desk Converts From Standing to Sitting With One Button

Buzz60 (Oct. 24, 2014) IKEA is out with a new convertible desk that can convert from a sitting desk to a standing one with just the push of a button. Jen Markham explains. Video provided by Buzz60
Powered by NewsLook.com
Ebola Protective Suits Being Made in China

Ebola Protective Suits Being Made in China

AFP (Oct. 24, 2014) A factory in China is busy making Ebola protective suits for healthcare workers and others fighting the spread of the virus. Duration: 00:38 Video provided by AFP
Powered by NewsLook.com
Real-Life Transformer Robot Walks, Then Folds Into a Car

Real-Life Transformer Robot Walks, Then Folds Into a Car

Buzz60 (Oct. 24, 2014) Brave Robotics and Asratec teamed with original Transformers toy company Tomy to create a functional 5-foot-tall humanoid robot that can march and fold itself into a 3-foot-long sports car. Jen Markham has the story. Video provided by Buzz60
Powered by NewsLook.com
Police Testing New Gunfire Tracking Technology

Police Testing New Gunfire Tracking Technology

AP (Oct. 24, 2014) A California-based startup has designed new law enforcement technology that aims to automatically alert dispatch when an officer's gun is unholstered and fired. Two law enforcement agencies are currently testing the technology. (Oct. 24) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins