Evidence: The Destruction of the World Trade Center

On 9/11/2001, the World Trade Center, a complex of 7 steel-framed buildings in Lower Manhattan, was totally destroyed. All three skyscrapers in the complex were leveled, including WTC 7, a 47-story building on the block north of the original 6-building complex.

Contents

• Design claims
  • Worthington, Skilling, Helle & Jackson white paper
  • The Richard Roth telegram
  • Engineering News Record
• Construction
• Destruction
  • Visual records
  • Oral histories
• Remains
  • Visual records
  • Scientific reports

Design Claims

Worthington, Skilling, Helle & Jackson White Paper

A white paper on the structure of the Twin Towers carried out by the firm of Worthington, Skilling, Helle & Jackson contained eleven numbered points, including:

3. The buildings have been investigated and found to be safe in an assumed collision with a large jet airliner (Boeing 707-DC 8) traveling at 600 miles per hour. Analysis indicates that such collision would result in only local damage which could not cause collapse or substantial damage to the building and would not endanger the lives and safety of occupants not in the immediate area of impact.

--City in the Sky, p 131

Glanz and Lipton summarize the findings of the white paper:

The Vierendeel trusses would be so effective, according to the engineers' calculations, that all the columns on one side of a tower could be cut, as well as the two corners and several columns on the adjacent sides, and the tower would still be strong enough to withstand a 100-mile-per-hour wind.
--City in the Sky, p 133

The Richard Roth Telegram

A telegraph from the architectural firm Richard Roth, partner at Emery Roth & Sons, was distributed to reporters on February 14, 1965. The telegraph was in response to claims by real estate baron and Lawrence Wien that the design of the Twin Towers was unsound.

THE STRUCTURAL ANALYSIS CARRIED OUT BY THE FIRM OF WORTHINGTON, SKILLING, HELLE & JACKSON IS THE MOST COMPLETE AND DETAILED OF ANY EVER MADE FOR ANY BUILDING STRUCTURE. THE PRELIMINARY CALCULATIONS ALONE COVER 1,200 PAGES AND INVOLVE OVER 100 DETAILED DRAWINGS.
...
4. BECAUSE OF ITS CONFIGURATION, WHICH IS ESSENTIALLY THAT OF A STEEL BEAM 209' DEEP, THE TOWERS ARE ACTUALLY FAR LESS DARING STRUCTURALLY THAN A CONVENTIONAL BUILDING SUCH AS THE EMPIRE STATE BUILDING WHERE THE SPINE OR BRACED AREA OF THE BUILDING IS FAR SMALLER IN RELATION TO ITS HEIGHT.
...
5. THE BUILDING AS DESIGNED IS SIXTEEN TIMES STIFFER THAN A CONVENTIONAL STRUCTURE. THE DESIGN CONCEPT IS SO SOUND THAT THE STRUCTURAL ENGINEER HAS BEEN ABLE TO BE ULTRA-CONSERVATIVE IN HIS DESIGN WITHOUT ADVERSELY AFFECTING THE ECONOMICS OF THE STRUCTURE. ...
--City in the Sky, p 134-6

Engineering News Record

The Engineering News Record (ENR) contained a number of articles on the design and construction of the World Trade Center. The article "How Columns Will Be Designed for 110-Story Buildings" quotes lead architect John Skilling:

"live loads on these [perimeter] columns can be increased more than 2000% before failure occurs."
--John Skilling, in Engineering News Record, 4/2/1964

Construction

9-11 Research pages on the history, architecture, and construction of the Twin Towers:

• The Towers' History: Origins of the World Trade Center and the World's Tallest Buildings
• Towers' Design Parameters: Twin Towers' Designers Anticipated Jet Impacts Like September 11th's
• The Towers' Architecture: The Innovative Design of the World Trade Center Towers
• Twin Towers Construction: Photographic Evidence of the Twin Towers' Construction

Destruction

On the day of 9/11, 2001, the three skyscrapers of the World Trade Center complex were totally destroyed, Structural collapse due to a combination of structural damage and fire is the reason given by official reports for the leveling of 110-story WTC 1 (the North Tower), 110-story WTC 2 (the South Tower), and 47-story WTC 7, with strong emphasis on the role of fires. That would make these the only three cases in history tall steel-framed structures collapsing mostly or entirely due to fires.

Visual Records

The attack on New York City was captured by numerous photographers and videographers, in many cases at great personal risk. Of the five major events -- the two jetliner impacts and total destruction of the three skyscrapers -- all but the first were recorded by numerous photographs and videos.

• WTC Attack Photos: Surviving Photographic Evidence of the World Trade Center Attack
  9-11 Research
• World Trade Center
  Aman Zafar
• World Trade Center Attack Memories and Photographs
  Richard Lethin
• Seeing the Horror, Part II
  Peter Turnley, Bill Biggart, David Turnley, Chip East, Aris Economopoulos

Oral Histories

An extensive body of evidence consisting of statements by 503 firefighters, paramedics, and emergency medical technicians who witnessed the events in New York City on 9/11/2001 was collected between October of 2001 and January of 2002 on the order of Thomas Von Essen, the city fire commissioner until he was succeeded by Nicholas Scoppetta in January of 2002. The New York Times sought the release of this evidence, filing a Freedom of Information Act lawsuit against the city, which was refusing to release the transcripts. On August 12, 2005, the Times announced that it would publish the transcripts of the "oral histories" and promptly did so.

• Full set of transcripts in PDF format
• Partial set of transcripts in text format

Remains

The destruction of the World Trade Center left a debris field covering the 16-acre site of the Center and extending several hundred feet beyond in all directions.

Visual Records

• High-resolution photograph of Ground Zero from 3,300 feet above
  NOAA
• The Anonymous Photographer collection
• Photographs by Lane Johnson of WTC remains at JFK hangar
• Ground Zero: Photographic Evidence of the Twin Towers' Remains
  9-11 Research

Scientific Reports

Data on the nature and conditions of the remains of the World Trade Center were gathered by a variety of agencies, including the U.S. Geological Survey (USGS), and National Oceanic and Aeronautics Administration (NOAA). Independent researchers supplied additional analysis using this data and physical evidence in the form of World Trade Center dust collected by individuals on 9/11/2001.

• Images of the World Trade Center Site Show Thermal Hot Spots on September 16 and 23, 2001.
  USGS
• An Initial Microstructural Analysis of A36 Steel from WTC Building 7
  JOM
• Appendix C: Limited Metallurgical Examination
  ASCE/FEMA
• Characterization of the Dust/Smoke Aerosol that Settled East of the World Trade Center (WTC) in Lower Manhattan after the Collapse of the WTC 11 September 2001
  EHP
• The DELTA Group: World Trade Center Data
  UCDavis
• Environmental Anomalies at the World Trade Center: Evidence for Energetic Materials
  The Environmentalist
• Active Thermitic Material Discovered in Dust from the 9/11 World Trade Center Catastrophe
  The Open Chemical Physics Journal