2. Observed Temperatures around 1000°C and Sulfidation in WTC 7 Steel


One of the relatively few previous peer-reviewed papers relating to the WTC collapses provides “An Initial Microstructural Analysis of A36 Steel from WTC Building 7.”


This brief but important letter states:

While the exact location of this beam could not be determined, the unexpected erosion of the steel found in this beam warranted a study of microstructural changes that occurred in this steel. Examination of other sections in this beam is underway.



Rapid deterioration of the steel was a result of heating with oxidation in combination with intergranular melting due to the presence of sulfur.


The formation of the eutectic mixture of iron oxide and iron sulfide lowers the temperature at which liquid can form in this steel. This strongly suggests that the temperatures in this region of the steel beam approached ~1000°C by a process similar to making a “blacksmith’s weld” in a hand forge.

(Barnett, 2001)

How were these ~1000°C temperatures in the steel beam achieved? As noted above in the quotation from Eagar, it is difficult to reach temperatures above 650°C in the type of diffuse fires evident in the WTC buildings, let alone in the steel columns where heat is transported away by the enormous heat sink of the steel structure. So the high temperatures deduced by Barnett, Biederman and Sisson are indeed remarkable.

Then there is the rather mysterious sulfidation of the steel reported in this paper—What is the origin of this sulfur? No solid answer is given in any of the official reports.

Of course, there is a straightforward way to achieve 1000°C temperatures (and well above) in the presence of sulfur, and that is to use thermate (or a similar variation of thermite). Thermate is a high-level thermite analog containing sulfur developed by the military. Thermate combines aluminum/iron oxide (thermite) with barium nitrate (29%) and sulfur (typically 2% although more sulfur could be added).


The thermate reaction proceeds rapidly and is much faster than thermite in degrading steel leading to structural failure. Thus, both the unusually high temperatures and the extraordinary observation of steel-sulfidation (Barnett, 2001) can be accounted for—if the use of thermate is allowed in the discussion. Note that other oxidizers (like KMnO4) and metals (like titanium and silicon) are commonly used in thermite analogs.


Finally, sulfidation was observed in structural steel samples found from both WTC7 and one of the WTC Towers, as reported in Appendix C in the FEMA report. It is quite possible that more than one type of cutter-charge was involved on 9/11, e.g., HMX, RDX and thermate in some combination. While gypsum in the buildings is a source of sulfur, it is highly unlikely that this sulfur could find its way into the structural steel in such a way as to form a eutectic. The evidence for the use of some variant of thermite such as sulfur-containing thermate in the destruction of the WTC Towers and building 7 is sufficiently compelling to warrant serious investigation.


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3. Near-Symmetrical Collapse of WTC 7

As you observed (link above), WTC 7 collapsed rapidly and nearly-straight-down symmetrically—even though fires were randomly scattered in the building. WTC 7 fell about seven hours after the Towers collapsed, even though no major persistent fires were visible (considerable dark smoke was seen).


There were twenty-four huge steel support columns inside WTC 7 as well as huge trusses, arranged non-symmetrically, along with some fifty-seven perimeter columns, as indicated in the diagram below (FEMA, 2002, chapter 5; NIST, 2005).

Diagram showing steel-column arrangement in WTC 7, view looking down on the roof. Circled columns in red were possibly damaged due to debris from WTC 1 collapse, some 350 feet away (NIST, 2005) so the damage was clearly non-symmetrical, and evidently, none of the core columns was severed by falling debris. WTC 7 was never hit by a plane.

A near-symmetrical collapse, as observed, evidently requires the simultaneous “pulling” of many of the support columns (see below, particularly discussion of Bazant & Zhou paper). The likelihood of complete and nearly-symmetrical collapse due to random fires as in the “official” theory is small, since non-symmetrical failure is so much more likely.


If one or a few columns had failed, one might expect a portion of the building to crumble while leaving much of the building standing. For example, major portions of WTC 5 remained standing on 9/11 despite very significant impact damage and severe fires.

Non-symmetrical collapse of tall buildings when due to random causes. L’Ambiance Plaza collapse (far above) shows how pancaked concrete floor slabs are largely intact and clearly reveal stacking effects with minimal fine dust, as expected from random progressive collapse. By contrast, concrete floors in the Twin Towers and WTC 7 were pulverized to dust—as is common in controlled demolitions using explosives.


On the other hand, a major goal of controlled demolition using cutter-charges/explosives is the complete and straight-down-symmetrical collapse of buildings. The reader may wish to review controlled-demolition examples here, for examples of complete symmetrical collapses due to carefully pre-positioned explosives. (The videos of the Philips Building, Southwark Towers, and Schuylkill Falls Tower collapses are particularly instructive.)

Concluding remarks in the FEMA report on the WTC 7 collapse lend support to these arguments:

The specifics of the fires in WTC 7 and how they caused the building to collapse [“official theory"] remain unknown at this time. Although the total diesel fuel on the premises contained massive potential energy, the best hypothesis [fire/debris-damage caused collapse] has only a low probability of occurrence. Further research, investigation, and analyses are needed to resolve this issue.

(FEMA, 2002, chapter 5; emphasis added.)

That is precisely the point: further investigation and analyses are indeed needed, including serious consideration of the controlled-demolition hypothesis which is neglected in all of the government reports (FEMA, NIST and 9-11 Commission reports).


Note that the 9-11 Commission report does not even mention the collapse of WTC 7 on 9-11-01. (Commission, 2004) This is a striking omission of data highly relevant to the question of what really happened on 9-11.


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4. No Previous Skyscraper Complete Collapse Due to Fires


A New York Times article entitled “Engineers are baffled over the collapse of 7 WTC; Steel members have been partly evaporated,” provides relevant data.

Experts said no building like it [WTC7], a modern, steel-reinforced high-rise, had ever collapsed because of an uncontrolled fire. (Glanz, 2001; emphasis added.)

Fire engineering expert Norman Glover agrees:

  • Almost all large buildings will be the location for a major fire in their useful life.

  • No major high-rise building has ever collapsed from fire…

  • The WTC [itself] was the location for such a fire in 1975; however, the building survived with minor damage and was repaired and returned to service.”

    (Glover, 2002)

That’s correct – no steel-beam high-rise had ever before (or since) completely collapsed due to fires! However, such complete and nearly symmetrical collapses in tall steel-frame buildings have occurred many times before—all of them due to pre-positioned explosives in a procedure called “implosion” or controlled demolition. What a surprise, then, for such an occurrence in downtown Manhattan— three skyscrapers completely collapsed on the same day, September 11, 2001, presumably without the use of explosives.

Engineers have been trying to figure out exactly what happened and whether they should be worried about other buildings like it around the country… Most of the other buildings in the [area] stood despite suffering damage of all kinds, including fire...

‘Fire and the structural damage …would not explain steel members in the debris pile that appear to have been partly evaporated’, Dr. [Jonathan] Barnett said.

(Glanz, 2001; emphasis added.)

The observed “partly evaporated” steel members is particularly upsetting to the official theory, since fires involving paper, office materials, even diesel fuel, cannot generate temperatures anywhere near the ~5,180 oF (~2860 oC) needed to evaporate steel. (Recall that WTC 7 was not hit by a jet, so there was no jet fuel involved in the fires in this building.)


However, thermite-variants, RDX and other commonly-used incendiaries or explosives (i.e., cutter-charges) can readily slice through steel, thus cutting the support columns in a controlled demolition, and reach the required temperatures. This mystery needs to be explored – but is not mentioned in the “official" 9-11 Commission or NIST reports.


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5. Squib-timing during the Collapse of WTC 7

Horizontal puffs of smoke and debris are observed emerging from WTC-7 on upper floors, in regular sequence, just as the building starts to collapse. (The reader may wish to view the close-up video clip again.) The upper floors have evidently not moved relative to one another yet, from what one can observe from the videos. In addition, the timing between the puffs is less than 0.2 seconds so air-expulsion due to collapsing floors (see Chertoff, 2005) is evidently excluded.


Free-fall time for a floor to fall down to the next floor is significantly longer than 0.2 seconds: the equation for free fall, y = ½ gt2, yields a little over 0.6 seconds, as this is near the initiation of the collapse.

However, the presence of such “squibs” proceeding up the side of the building is common when pre-positioned explosives are used, as can be observed here. The same site shows that rapid timing between explosive squibs is also common. (It is instructive to view several of the implosion videos at this web site.) Thus, squibs as observed during the collapse of WTC 7 going up the side of the building in rapid sequence provide additional significant evidence for the use of pre-placed explosives.


Release by the government (NIST, in particular) of all videographic and photographic data showing details of the fires, damage, and collapse of WTC 7 on 9/11/2001would allow us to analyze these squib data in greater detail, to determine whether breaking windows or explosive charges are evidenced in the observed puffs of smoke. Horizontal plumes and sounds of explosions are even more pronounced in available videos of the collapses of the WTC Towers (see sections 7 and 8 below).

Regarding this highly-secure building, a NY Times article entitled “Secretive C.I.A. Site in New York was Destroyed on Sept. 11,” provides an intriguing puzzle piece:

“The C.I.A.’s undercover New York station was in the 47-story building at 7 World Trade Center… All of the agency’s employees at the site were safely evacuated… The intelligence agency’s employees were able to watch from their office windows while the twin towers burned just before they evacuated their own building.” (Risen, 2001)

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6. Early Drop of North Tower Antenna

The official FEMA 9-11 report admits a striking anomaly regarding the North Tower collapse:

Review of videotape recordings of the collapse taken from various angles indicates that the transmission tower on top of the structure began to move downward and laterally slightly before movement was evident at the exterior wall. This suggests that collapse began with one or more failures in the central core area of the building.

(FEMA, 2002, chapter 2; emphasis added.)

North Tower showing antenna (top) at beginning of collapse.

Yes, we can see for ourselves that the antenna drops first from videos of the North Tower collapse.



A NY Times article also notes this behavior:

The building stood for more than an hour and a half. Videos of the north tower’s collapse appear to show that its television antenna began to drop a fraction of a second before the rest of the building. The observations suggest that the building’s steel core somehow gave way first…

(Glanz and Lipton, 2002; emphasis added)

But how? What caused the 47 enormous steel core columns of this building which supported the antenna to evidently give way nearly simultaneously, if not cutter charges?

The anomalous early antenna-drop was noted by the FEMA report (FEMA, 2002) and the New York Times (Glanz and Lipton, 2002) yet not resolved in the official reports
(FEMA, 2002; Commission, 2004; NIST, 2005).


The NIST report notes that:

...photographic and videographic records taken from due north of the WTC 1 collapse appeared to indicate that the antenna was sinking into the roof {McAllister 2002}. When records from east and west vantage points were viewed, it was apparent that the building section above the impact area tilted to the south as the building collapsed.

(NIST, 2005)

However, we find no quantitative analysis in the report which shows that this tilting of the building section was sufficient to account for the large apparent drop of the antenna as seen from the north, or that this building-section-tilting occurred before the apparent antenna drop. Furthermore, the FEMA investigators also reviewed “videotape recordings of the collapse taken from various angles” yet came to the sense that,

“collapse began with one or more failures in the central core area of the building.”

(FEMA, 2002)

Quantitative analysis needs to be done and shown to resolve the issue.

Gordon Ross has written a scholarly paper on the collapse of WTC 1, which carefully considers conservation of momentum and conservation of energy, here. He shows that even if the Tower started to collapse due to fire and damage, it would not continue to complete collapse.


Note that the collapse of the McCormick Place building in Chicago is an example of a partial collapse only of a steel-frame building due to fire. The roof collapsed, but since the walls of that one-story building remained standing, it is clearly not comparable to the complete collapses of three WTC skyscrapers on 9/11/2000.


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7. Eyewitness Accounts of Flashes and Loud Explosions

Multiple loud explosions in rapid sequence were heard and reported by numerous observers in and near the WTC Towers, consistent with explosive demolition. Firemen and others described flashes and explosions in upper floors near where the plane entered, and in lower floors of WTC 2 just prior to its collapse, far below the region where the plane had struck the tower (Dwyer, 2005).


For instance, at the start of the collapse of the South Tower a Fox News anchor reported:

There is an explosion at the base of the building… white smoke from the bottom… something happened at the base of the building! Then another explosion.”

(De Grand Pre, 2002, emphasis added.)

Firefighter Edward Cachia independently reported:

[We] thought there was like an internal detonation, explosives, because it went in succession, boom, boom, boom, boom, and then the tower came down…It actually gave at a lower floor, not the floor where the plane hit. (Dwyer, 2005; emphasis added.)

And Assistant Fire Commissioner Stephen Gregory provides additional insights:

When I looked in the direction of the Trade Center before it came down, before No. 2 came down, ..I saw low-level flashes. In my conversation with Lieutenant Evangelista, never mentioning this to him, he questioned me and asked me if I saw low-level flashes in front of the building, and I agreed with him because I thought—at that time I didn’t know what it was. I mean, it could have been as a result of the building collapsing, things exploding, but I saw a flash flash flash and then it looked like the building came down.

Q. Was that on the lower level of the building or up where the fire was?


A. No, the lower level of the building. You know like when they demolish a building, how when they blow up a building, when it falls down? That’s what I thought I saw. And I didn’t broach the topic to him, but he asked me. He said I don’t know if I’m crazy, but I just wanted to ask you because you were standing right next to me… He said did you see any flashes? I said, yes, well, I thought it was just me.

He said no, I saw them, too... I mean, I equate it to the building coming down and pushing things around, it could have been electrical explosions, it could have been whatever.”

(Dwyer, 2005, Assistant Commissioner Stephen Gregory FDNY WCT2 File No. 91 10008; emphasis added.)

It is highly unlikely that jet fuel was present to generate such explosions especially on lower floors, and long after the planes hit the buildings. Dr. Shyam Sunder, Lead Investigator for NIST stated:

“The jet fuel probably burned out in less than 10 minutes.”

(Field, 2005)

“Electrical explosions” would clearly be insufficient to bring a steel-frame skyscraper down, in any building built to code.


On the other hand, pre-positioned explosives provide a plausible and simple explanation for the observed detonations followed by complete building collapses. Thus, it cannot be said that “no evidence” can be found for the use of explosives. This serious matter needs to be treated as a plausible scientific hypothesis and thoroughly investigated.


118 Witnesses: The Firefighters’ Testimony to Explosions in the Twin Towers” by Graeme MacQueen provides significant details regarding eyewitness accounts.


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8. Ejection of Steel Beams and Debris-plumes from the Towers

The horizontal ejection of structural steel members for hundreds of feet and the pulverization of concrete to flour-like powder, observed clearly in the collapses of the WTC towers, provide further evidence for the use of explosives – as well-explained in http://911research.wtc7.net/talks/towers/index.html  (See also, Griffin, 2004, chapter 2.)


The observed plumes or “squibs” are far below the pulverization region and therefore deserving of particular attention. They appear much like the plumes observed in http://www.implosionworld.com/cinema.htm  (e.g., the controlled demolition of the Southwark Towers).

North Tower during top-down collapse.
Notice mysterious horizontal plumes far below pulverization region.

Unlike WTC7, the twin towers appear to have been exploded “top-down” rather than proceeding from the bottom – which is unusual for controlled demolition but clearly possible, depending on the order in which explosives are detonated.


That is, explosives may have been placed on higher floors of the towers and exploded via radio signals so as to have early explosions near the region where the plane entered the tower. Certainly this hypothesis ought to be seriously considered in an independent investigation using all available data.


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