Descriptions of Jet Fuel Dispersion in the Towers

 
For an excellent summary of the official studies of the collapse of the Twin Towers, see NIST Investigation of the World Trade Center Disaster – Frequently Asked Questions


Of the evacuees interviewed by NIST, 72% reported the smell of fuel fumes in the stairwells of the north tower, and 63% in the south tower. (NIST NCSTAR 1-7A p. 17)


From NIST NCSTAR 1 Federal Building and Fire Safety Investigation of the World Trade Center Disaster: Final Report of the National Construction Safety Team on the Collapses of the World Trade Center Towers

North Tower

South Tower

A three year study into the collapse of the towers found that airplane debris sliced through utility shafts in both towers' cores, creating conduits for burning jet fuel and fiery destruction throughout the buildings.

Supplement to the report notes that elevator lobbies throughout the building were particularly affected by the airplane impacts, likely by the excess jet fuel ignited by the crash pouring down the elevator shafts.

NIST lead investigator Shyam Sunder explains that the burning jet fuel simply followed the path of least resistance. The core of the building is where a large number of elevator shafts and stairwells were damaged. These provided an easy path for jet fuel to traverse down," Sunder tells Pop Mechanics.

NIST investigators spoke with more than 1,000 survivors and witnesses of the attack as part of their attempt to determine the progression of damage to the buildings. A number of witnesses reported seeing pockets of fire in locations far from floors directly affected by the aircraft impacts.

NIST granted all witnesses anonymity in exchange for their cooperation- One witness, near an elevator between the 40th and 50th floors of the North Tower recalled,

"I saw the elevator in front of me had flames coming out of it. The elevator was closed but the flames came from the front where the doors meet and on the sides...I saw a chandelier shaking; it was really moving...black smoke started filling the corridor, it got really dense fast." And a survivor in the basement of the North Tower at the time of the attack recalled, "I saw a big bright orange color coming through the basement with the smoke...A fireball came shooting out the basement door."

Investigators heard additional reports that some elevators "slammed right down" to the ground floor in loud violent crashes. The doors cracked open on the lobby floor and flames came out and people died", says James Quintiere, an engineering professor at the University of Maryland and a NIST adviser. A similar observation was made by Jules and Gedeon Naudet. On the day of the attacks, the French brothers were making a documentary about Tony Benetatos, a rookie NY City firefighter blocks from the WTC. Benetatos became one of the first responders to the N Tower. As Jules Naudet followed him into the lobby, minutes after the first aircraft struck, the filmmaker saw victims on fire, a scene he found too horrific to record.
Highly recommended for its powerful footage inside the north tower shortly after the impact of flight 11, and of the collapse of the south tower as experienced in the north tower lobby: the Naudet Brothers' "9/11 – The Filmmakers' Commemorative Edition."


From USA Today: "Elevators Were Disaster in Disaster" (2002)
Elevator shafts worked like chimneys, funneling unbearable smoke to floors above the crashes. The shafts also channeled burning jet fuel throughout both towers. Fire moved not only up and down but also side to side, from shaft to shaft, unleashing explosions in elevator lobbies and in restrooms next to the shafts.

USA TODAY made an intensive effort over the past six months to determine what happened to the World Trade Center elevators. Reporters interviewed more than 50 people who were in elevators at the time the jets hit or moments before. The newspaper also reviewed 2,500 pages of accounts written by survivors and reports in other media outlets, examined architectural plans and spoke to elevator experts and mechanics who worked at the Trade Center.

The result is the first in-depth look at an important but neglected part of the World Trade Center disaster.

From “In Data Trove, a Graphic Look at Towers' Fall” By James Glanz and Eric Lipton, The New York Times, October 29, 2002
(Of the Silverstein/Weidlinger study)
…"Taken in the aggregate, it represents a milestone in the forensic engineering of a disaster." said Jeremy Isenberg, a member of the National Academy of Engineering and president of Weidlinger Associates, where some of the work was done, who believes the information can be used to build safer skyscrapers and to better understand the risks posed by existing ones. "I have never seen this level of technical knowledge and experience brought to bear on a single problem."

The mass of documents and analysis was complied over the last year by a kind of dream team of engineering experts as the two litigants weighed in on the question of how much Mr. Silverstein should be compensated for the loss of the towers. Mr. Silverstein says that he is owned about $7 billion, the insurance companies half that.

…Next, of course, came the fire. By assembling thousands of photographs, videos and witness accounts, Richard L.P. Custer, the national technical director of ArupFire, a Massachusetts fire science company, prepared a color-coded map of each face of the two towers that shows the spread of fire and smoke from the moment the fireballs erupted until each of the towers collapsed.
What emerges from this analysis and a separate fire survey by Exponent Failure Analysis may help explain why everyone in the two floors just below the plane impact in the north tower ultimately died, even if they survived the initial impacts. In the south tower, most people below impact survived and were able to flee.



...As the American Airlines Flight 11 rammed onto the north tower, the jet fuel was sprayed into a much larger area within the tower, the analysis shows. It documents office workers who reported burning ceilings, floors and elevators at locations throughout the lower reaches of the north tower. Flames even reached the north tower lobby, where several people were severely burned as they stood near the elevators.

 The rapid and wide dispersion of the fuel apparently ignited fires on the 92nd and 93rd floors of the north tower, just below the impact zone, where Carr Futures and Marsh & McLennan had their offices. The fires also engulfed another series of floors just above impact and they somehow spread to the offices of Cantor Fitzgerald in the tower's upper reaches, possibly through a mechanical shaft, the analysis finds.


From “Courage Above and Beyond the Call of Duty: A Report of the September 11, 2001 Experiences of Port Authority Engineers at the World Trade Center
From the South Tower FCC (Fire Command Center), Amatuccio now joined by Riccardelli established two-way communication with Bobbitt and Parente who were manning the North Tower FCC. They continued to work with the firemen in both towers, in spite of the danger to which they were exposed from debris that was falling from the tower floors above. The smell of burning jet fuel was becoming more and more prevalent at the FCC levels in both buildings.