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Note from the editors regarding: 15 years later: On the physics of high-rise building collapses

With regard to the publication of the article "15 years later: On the physics of high-rise building collapses", the Editors of Europhysics News have contacted the National Institute of Science and Technology in the USA to share their conclusions. Their summary is provided below:

NIST Position on the WTC investigation

The NIST WTC investigation team members feel that since our study of the World Trade Center building (WTC 1, 2 and 7) collapses ended in 2008, there has been no new evidence presented that would change our findings and conclusions, and therefore, nothing new that we can contribute to the discussion. NIST firmly stands behind its investigation results, and that the body of evidence still overwhelmingly leads to the following scenarios:

  • The WTC Towers collapsed because aircraft impact damage and debris dislodged fireproofing from critical steel components, jet fuel-initiated fires burned very hot for long duration when fed by debris and office materials, and the heat eventually weakened the exposed steel until it lost integrity and led to a global failure; and
  • WTC 7 collapsed because damage caused by debris from the falling WTC 1 ignited fires on multiple floors, the heat expanded and dislodged a beam connecting a key perimeter column to both a long-span central beam and a critical internal support column, and the column’s failure set off a chain reaction of failures across the building’s steel infrastructure.

Our comprehensive website, http://wtc.nist.gov, covers all aspects of the WTC investigation and provides three sets of "frequently asked questions" (on the overall investigation, the WTC towers and WTC 7) that address—based solely on our findings—many of the claims made by those holding alternative views as to how the three WTC buildings collapsed.

The NIST investigation into the collapses of WTC Buildings 1, 2 and 7 was the most detailed examination of structural failure ever conducted. Based on the recommendations from this investigation, two sets of major and far-reaching building and fire code changes have been adopted by the International Code Council (ICC) into the ICC’s I-Codes (specifically the International Building Code, or IBC, and the International Fire Code, or IFC). The 40 code changes were adopted less than five years from the release of the final report on WTC 1 and 2, and less than two years following the release of the final report on WTC 7. This is an extraordinarily rapid pace in the code making and approval process—a solid affirmation by the ICC that the work done by the NIST WTC investigation team was of the highest quality and critical to ensuring that future buildings—especially tall structures—will be increasingly resistant to fire, more easily evacuated in emergencies, more accessible to first responders when needed, and most importantly, safer overall.

Michael E. Newman
Senior Communications Officer
Public Affairs Office
National Institute of Science and Technology
100 Bureau Drive, Stop 1070
Gaithersburg, MD 20899-1070


It is the policy of EPN to publish by invitation. Prospective authors are suggested by members of our Editorial Advisory Board, who cover various disciplines and are from various countries. This particular Feature article 'On the physics of high-rise buildings collapses', related to the attack on the WTC, followed the same route. We expected this topic to be of wide interest to our readers and thus invited the suggested authors to submit their manuscript. EPN does not have a formal review/rejection policy for invited contributions. In the present case we realized that the final manuscript contained some speculations and had a rather controversial conclusion. Therefore a 'Note from the editors' was added, stressing that the content is the sole responsibility of the authors and does not represent an official position of EPN.

Since some controversy remains, even among more competent people in the field, we considered that the correct scientific way to settle this debate was to publish the manuscript and possibly trigger an open discussion leading to an undisputable truth based on solid arguments. Criticism and comments in the form of Letters to the Editor are welcome. It is shocking that the published article is being used to support conspiracy theories related to the attacks on the WTC. The Editors of EPN do not endorse or support these views.

In future, prospective authors will be asked to provide an abstract of the proposed article, as well as an indication of other publications to allow the editors to better assess the content of the invited articles.