NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.
Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.
An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
STRUCTURAL RESPONSE OF WTC 7 FLOOR SYSTEMS TO FIRE
Published
Author(s)
Therese P. McAllister
Abstract
The WTC 7 investigation by the National Institute of Standards and Technology (NIST) identified several factors that alone, or in combination, led to fire-induced failures of the floors, and subsequently, total collapse of the 47-story WTC 7 building. A sensitivity study is being conducted to determine the relative significance of the identified factors, which includes the presence or absence of shear studs on girders, connection types, and bay span lengths. The technical basis for the identified structural factors is presented in this paper.
McAllister, T.
(2010),
STRUCTURAL RESPONSE OF WTC 7 FLOOR SYSTEMS TO FIRE, Proceedings of the ASCE Structures Congress 2010, Orlando, FL, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=904926
(Accessed October 10, 2025)