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Background Attack Aftermath Evidence Misinformation Analysis Memorial

The Core Meltdown Theory

The Fire-Melts-Steel Idea Was Promoted by Experts

Moments before its collapse, the South Tower showed no externally visible flames and emitted only a thin veil of black smoke.

The claim that the fires in the Twin Towers melted the structural steel and thereby caused the collapses was promoted by numerous "experts" cited in media reports, starting on the day of the attack. Skeptics of the official story attacked this claim on the basis that open fires could not possibly elevate steel to temperatures required to melt it, starting with J. McMichael's Muslims Suspend the Laws of Physics. Despite the fact that the fire-melts-steel idea was introduced by media-cited experts, two of the highest-profile attacks on the 9/11 Truth Movement falsely accused skeptics of using the idea as a straw-man argument. 911Research exposes these disingenuous attacks.

Exaggeration in the media about the ferocity of the fires was rampant. The Stanford University News Service cited Stanford Professor Steven Block's comparison of the jet impacts to "nuclear bomb explosion[s]."

"Next to an atomic weapon, this is the most [energy] that you can pack in one punch."

The article introduces the idea that the fires "melted the buildings' cores".

Although the World Trade Center was designed to withstand "amazing kinds of forces" and even an aircraft collision, architects may not have taken into consideration the enormous amount of heat a plane loaded with enough fuel to fly across the country would generate. The intense heat could have melted the buildings’ cores, allowing for the collapses, he suggested. 1  

Writing for Scientific American, Michael Shermer described the fires as "inferno[s] throughout each building." Seconds after the South Tower collapsed, ABC reporter Don Dahler interpreted the event to an incredulous Peter Jennings, stating: "the top part of the building was totally involved in fire."

The novel comparison of building fires to nuclear reactions, and the suggestion that the massive steel core structures melted, has prompted us to label this idea the "core meltdown theory."

Parade of Experts Endorse Melted Steel Claim

On the afternoon of 9/11/01 NBC News interviewed Hyman Brown, erroneously described as the project engineer for the construction of the Twin Towers. 2   Brown suggested that the melting of steel is inevitable when fireproofing fails.

Structural steel is fireproofed to last between one and two hours, which it did, and then steel melts. 3  

O'Neil goes on to paraphrase Brown as saying that the Towers were built to withstand 200-mph hurricanes.

A number of news reports on the day following the attack spoke of melted steel. A report in the Arizona Daily Wildcat, entitled "Intense Heat Melted Steel Supports in Trade Center" quoted a structural engineer Richard Ebeltoft on the subject of fires melting steel:

Richard Ebeltoft, a structural engineer and University of Arizona architecture lecturer, speculated that flames fueled by thousands of gallons of aviation fuel melted the building's steel supports. 4  

Hyman Brown is quoted again on September 12th in an AP article.

Hyman Brown, a University of Colorado civil engineering professor and the Trade Center's construction manager [sic], speculated that flames fuelled by thousands of litres of aviation fuel melted steel supports.

"This building would have stood had a plane or a force caused by a plane smashed into it," he said. "But steel melts, and 90,850 litres of aviation fluid melted the steel. Nothing is designed or will be designed to withstand that fire." 5  

In some cases, press reports made the claim that the WTC fires melted steel, when the experts they cited only spoke of the fires softening the steel. For example, the Baltimore Sun ran the headline Jet Fuel-Fed Fire May Have Melted Steel in Towers for an article in which Mark Loizeaux, president of Controlled Demolition Inc., states that "the heat from the fire softened the Towers' steel columns 'like a piece of taffy would become soft in the sun'," but does not claim that steel melted. 6  

A September 12th article in NewScientist.com endorsed the fire-melts-steel idea.

Each Tower was struck by a passenger aeroplane, hijacked by suicidal terrorists, but remained upright for nearly an hour. Eventually raging fires melted the supporting steel struts, but the time delay allowed hundreds of people to escape. 7  

A BBC report from September 13 quoted structural engineer Chris Wise asserting that the fires melted the steel.

It was the fire that killed the buildings. There's nothing on earth that could survive those temperatures with that amount of fuel burning. The columns would have melted, the floors would have melted and eventually they would have collapsed one on top of each other. 8  

A September 14 report in the Cincinnati Business Courier paraphrases Elmer Obermeyer, president and chairman of Graham Obermeyer & Partners Ltd., a structural engineering firm in downtown Cincinnati. Obermeyer is considered the "guru in his field" according to the article.

Obermeyer said the fire probably melted the steel beams of the World Trade Center towers, which were never designed to survive the kind of shot they took Sept. 11. 9  

On September 17, the BBC quoted another expert, professor of structural engineering at the University of Newcastle, John Knapton, on the subject of melted steel.

"The buildings survived the impact and the explosion but not the fire, and that is the problem."

"The 35 tonnes of aviation fuel will have melted the steel... all that can be done is to place fire resistant material around the steel and delay the collapse by keeping the steel cool for longer." 10  

M.I.T. professor of civil and environmental engineering Eduardo Kausel endorsed the fire-melts-steel idea a month after the attack, as a panelist at a public event in Cambridge, MA.

I believe that the intense heat softened or melted the structural elements--floor trusses and columns--so that they became like chewing gum, and that was enough to trigger the collapse. 11  


1. Stanford Scientist Compares Impact of World Trade Center Attack to a Nuclear Bomb Explosion, Stanford.edu, 9/11/01 [cached]
2. 'Chief Engineer' Hyman Brown by Patrick Marks, colorado911visibility.org,
3. Special Report, NBC News, 9/11/01
4. Intense Heat Melted Steel Supports in Trade Center, Arizona Daily Wildcat, 9/12/01 [cached]
5. Kamikaze Attackers May Have Known Twin Sisters' Weak Spot, SundayTimes.co.za, 9/12/01 [cached]
6. Jet Fuel-Fed Fire May Have Melted Steel in Towers, BaltimoreSun.com, 9/12/01 [cached]
7. Design Choice for Towers Saved Lives, NewScientist.com, 9/12/01 [cached]
8. How the World Trade Center fell, BBC, 9/13/01
9. Carew Tower Couldn't Tolerate Similar Strike, Business Courier, 9/14/01 [cached]
10. Twin Towers' Steel Under Scrutiny, BBC, 9/17/01 [cached]
11. When the Twin Towers Fell, Scientific American, 10/9/01

page last modified: 2010-10-22