Prelude 9/11 morning Flight 11 hijacked Flight 175 hijacked WTC 1 hit Flight 77 hijacked WTC 2 hit Flight 93 hijacked Pentagon hit WTC 2 collapses Flight 93 crashes WTC 1 collapses WTC 7 collapses Epilogue

Other technical studies

A number of investigations were also carried out, in addition to the in-depth scientific and technical investigations of the terror attacks. This is an ever-growing list of these reports.

American Society of Civil Engineers

ASCE, The Pentagon Building Performance Report

After the terror attacks, the American Society of Civil Engineers investigated the damaged Pentagon building, suggesting ways to improve the structure.
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Buro Happold

Fire Engineering of Steelwork
Phase 1 Report
Rev A.
February 2000


The international engineering company, Buro Happold, investigated in February 2000 how the fire protection in the World Trade Center 1 og 2 had been done.
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Environmental Health Perspectives

A monthly peer-reviewed journal, with research and news, published with the support of The National Institute of Environmental Health Sciences, National Institutes of Health, U.S. Department of Health and Human Services.

Health and Environmental Consequences of the World Trade Center Disaster,
Philip J. Landrigan, Paul J. Lioy, George Thurston, Gertrud Berkowitz, L. C. Chen, Steven N. Chillrud, Stephen H. Gavett, Panos G. Georggopoulos, Alison S. Geyh, Stephen Levin, Frederica Perera, Stephen M. Rappaport, Christopher Small, and the NIEHS World Trade Center Working Group
Environmental Health Perspectives, Vol. 112, No. 6, May 2004

World Trade Center fine particulate matter–chemistry and toxic respiratory effects: an overview.,
Stephen H Gavett

Chemical analysis of World Trade Center fine particulate matter for use in toxicologic assessment,
John K McGee, Lung Chi Chen, Mitchell D Cohen, Glen R Chee, Colette M Prophete, Najwa Haykal-Coates, Shirley J Wasson, Teri L Conner, Daniel L Costa, and Stephen H Gavett

Lawrence Berkeley National Laboratory

Elevated tritium levels at the World Trade Center

Lawrence Berkeley National Laboratory found traces of tritiated water (HTO) at the World Trade Center Ground Zero after the 9/11/01 terrorist attack. All these results are well below the levels of concern to human exposure.

Mailman School of Public Health, Columbia University

World Trade Center Environmental Contaminant Database, (WTCECD)
Tests included:

  • outdoor air, outdoor bulk dust, indoor air, and indoor dust wipes specifically in response to the disaster by the USEPA and NYSDEC; approximately 200 parameters are present, including particulate matter mass (PM2.5, PM10), volatile organic compounds (VOCs), dioxins, polychlorinated biphenyls (PCBs), metals, and asbestos.
  • air quality data reported to EPA’s Aerometric Information Retrieval System (AIRS) data repository from fixed-site air quality monitoring stations run by local, state and federal environmental agencies from 1970 to December 31, 2004. These include ozone, sulfur dioxide, nitrogen dioxide, carbon monoxide, lead, particulate matter mass (TSP, PM10, PM2.5) plus parameters measured on an irregular basis which include a suite of volatile organic compounds (VOCs), dioxins, polychlorinated biphenyls (PCBs), particle-associated metals, and limited meteorological data.

Massachusetts Institute of Technology (MIT)

The Towers Lost and Beyond
Essays on WTC, from the Massachusetts Institute of Technology (MIT), Eduardo Kausel (ed.)

Get the full report here PDF (9962KB).

  1. Preface
    Eduardo Kausel, PDF (15KB)
  2. A brief history of the WTC Towers
    John E. Fernandez, PDF (32KB)
  3. Inferno at the World Trade Center, NY
    Eduardo Kausel, PDF (19KB)
  4. Speed of aircraft
    Eduardo Kausel, PDF (856KB)
  5. Aircraft impact damage
    Tomasz Wierzbicki, Liang Xue, Meg Hendry-Brogan, PDF (5911KB)
  6. The fires
    Ahmed F. Ghoniem, PDF (537KB)
  7. Materials and structures
    Oral Buyukozturk, Franz-Josef Ulm, PDF (1442KB)
  8. Escaping with your life
    John E. Fernandez, PDF (937KB)
  9. Supply chains and terrorism
    Yossi Sheffi, PDF (80KB)
  10. The Reflecting Wall at MIT
    PDF (144KB)

MCEER

MCEER is an American organization, supported by e.g. the National Science Foundation and the Federal Emergency Management Agency (FEMA). MCEER investigates the effects of earthquakes and other catastrophes.

After the terror attacks, MCEER investigated the damaged buildings at Ground Zero, and published several reports.

Merritt & Harris

Merrit & Harris is a construction consultancy company, carrying out various technical investigations of buildings. In 2000, they were given the task of investigating the state of the World Trade Center 1 and 2. The reports were published in December, 2002, and include previous investigations made by other expert companies.

Report 1

Report 2

MVA Scientific Consultants

Progress Report on the Analysis of Red/Gray Chips in WTC Dust, Revised Report of Results: MVA9119, James R. Millette

James Millette, MVA Scientific Consultants, has conducted an independent study of dust samples from the World Trade Center, in an effort to replicate the experiments by Harrit et al. Millette concludes that there is no thermitic material in the dust.

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National Environmental Health Association

National Environmental Health Association is an organization working for better work environment. In 2003, they published this report about the health consequences of the impacted areas on Manhattan and in the vicinity of the Pentagon.
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Occupational Safety and Health Administration

The mission of the Occupational Safety and Health Administration is to assure safe and healthy working conditions for working men and women. In 2003, the administration published this report about the possible dangers for the rescue teams during the impacted areas on Manhattan.
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R.J. Lee Group / Deutsche Bank

Damage Assessment

130 Liberty Street Property
Report Date: December 2003
WTC Dust Signature Report
Composition and Morphology

Environmental study of dust from 130 Liberty Street, a.k.a. “Deutsche Bank” and “Bankers Trust Plaza”. The building was situated South of the World Trade Center 2.

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Signature Assessment

130 Liberty Street Property
Report Date: May 2004
Expert Report
WTC Dust Signature

A more detailed environmental study of the dust from 130 Liberty Street, a.k.a. “Deutsche Bank” and “Bankers Trust Plaza”. The building was situated South of the World Trade Center 2.

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Tnemec

Material Safety Data Sheet MSDS)

Chemical composition of the primer (paint) used to protect the steel used during the construction of the World Trade Center 1 and 2.
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USGS – United States Geological Survey

Environmental studies of the World Trade Center after the terror attacks on September 11th 2001.

Additional studies

The Washington Post

Database of the victims, The Washington Post

The Washington Post collated a database of the names of the victims of the terror attacks on September 11 2001.