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by Phil Molé
At the Hyatt Regency O?Hare near Chicago, a crowd of approximately 400 people has gathered on a pleasant summer evening. Some are old and some are young; some are dressed in colorful tie-died shirts while others wear dress shirts and slacks, but most seem cheerful and friendly. We are all waiting for the opening of the main lecture hall for the evening?s event, the first of many scheduled talks during a weekend-long conference. We bide some time by looking at the items for sale: DVD copies of Michael Moore?s Fahrenheit 9/11, the anti-Karl Rove documentary Bush?s Brain, and the more recent Walmart: The High Cost of Low Price.
There is nothing especially unusual here, since all of these are available at the Borders or Best Buy near you. But then as the doors to the main hall are about to open, one anxious attendee tries to start a chant of ?9/11 was an Inside Job.? A few people join in before another attendee tells him, quite emphatically, ?we already know!? The weekend conference is the Chicago meeting for 911truth.org, one of the most visible organizations within a larger coalition known as the ?9/11 Truth Movement,? and most of the crowd believes that the United States government planned and orchestrated the terrorist attacks of September
11, 2001.The statement ?we already know!? well summarizes the attitude of the conference attendees toward the material presented during the lectures. Many at the conference do not seem to be looking for new information that might lead to more accurate perspectives about the events of 9/11. A fellow sitting near me admits, ?We already know this stuff; we?re here to reconfirm what we already know.? The conference is a way for attendees to consolidate their group identity, and try to bring their message to those people at home and abroad who believe the ?official story? of 9/11. As someone who does not share the views of the 9/11 Truth Movement, I have another objective. I want to listen to their arguments and view their evidence, and understand the reasons why so many likable and otherwise intelligent people are convinced that the United States government planned the murder of nearly 3,000 of its own citizens. The Collapse of World Trade Center Buildings 1 & 2
When most of us recall the events of 9/11, we think of the image of those two seemingly indestructible World Trade Center towers crumbling to the ground. Not surprisingly, their collapse is also a central issue for the 9/11 Truth Movement. An overwhelming amount of the organization?s talks and publicity materials address the fall of Buildings 1 and 2. But as these materials show, 911truth.org does not believe the official story that the primary damage to the WTC occurred when two airplanes hijacked by terrorists crashed into the towers. Rather, they maintain that the towers fell due to a controlled demolition, planned in advance by the United States government.
Why do they think this? A primary reason seems to be that the collapse of the towers looks like the result of a controlled demolition. Since there is no structural resistance to gravity in a controlled demolition, the building collapses straight into its own footprint, with each floor ?pancaking? onto the floors below at or near the speed of a free fall. Many of the presenters at the Hyatt Conference compared videos of the collapse of the towers with videos of known controlled demolitions, noting the similarity in both the appearance and speed of collapse.
911truth.org maintains that if actually hit by an airplane, the steel structure of the WTC buildings should have provided at least some resistance to the weight of the floors above, causing the falling structure to pitch over to one side rather than pancake straight down. They further argue that fires caused by burning jet fuel from the crashed planes could not have caused the collapse, since jet fuel burns at a temperature of no more than 1500° Fahrenheit,1 while a temperature of approximately 2800° is needed to melt steel. David Heller makes the point in a widely read article:The official story maintains that fires weakened the buildings. Jet fuel supposedly burned so hot it began to melt the steel columns supporting the towers. But steel-framed skyscrapers have never collapsed from fire, since they?re built from steel that doesn?t melt below 2750° Fahrenheit. No fuel, not even jet fuel, which is really just refined kerosene, will burn hotter than 1500° Fahrenheit.2
Since burning jet fuel is not hot enough by itself to melt steel, reports that melted steel was observed at Ground Zero suggest to conspiracy theorists that some other incendiary substance must have been introduced.
Finally, many of the leaders of the movement claim that demolition ?squibs? can be seen in videos of the WTC collapse just before and during the time the towers began to fall. In professional demolition lingo, a ?squib? is an explosive device used to weaken building structure during a controlled demolition. Several presenters at the conference pointed out small bursts of debris spraying out horizontally from the towers during collapse, and identified these as ?squibs? secretly detonated to fell the buildings.
What can we make of these allegations? First, let?s examine the similarity in appearance between the collapse of the World Trade Center towers and the collapse of buildings destroyed through planned demolitions. In controlled demolitions, detonating devices weaken or disrupt all major support points in a building at the same time. Therefore, once the collapse begins, all parts of the building are simultaneously in motion, free-falling to the ground. However, this is definitely not what happens during the collapse of WTC Buildings 1 and
- Carefully review footage of the collapses, and you will find that the parts of the buildings above the plane impact points begin falling first, while the lower parts of the buildings are initially stationary.3 The parts of the towers below the impact point do not begin to fall until the higher floors have collapsed onto them. This is not what we would expect if the towers collapsed from a controlled demolition, but it is exactly what we would expect if the building collapse resulted from damage sustained by the impact of the planes and subsequent fire damage. A conspiracy theorist may counter that the buildings were rigged to begin falling from the top down, but what are the chances that those planning such a complicated demolition would be able to predict the exact location the planes would impact the towers, and prepare the towers to begin falling precisely there?
Additionally, footage of the collapse of the South Tower, or Building 2 reveals that the tower did not fall straight down, as the North Tower and buildings leveled by controlled demolitions typically fall. Instead, the tower tilted toward the direction of the impact point, and then began to pancake downward with the top part of the building tilted at an angle. The difference between the two collapses can be explained by the different way each airplane struck the buildings. The first plane struck the North Tower (Building 1) between the 94th to 98th floors and hit it head on, burrowing almost directly toward the core of the building. The second airplane struck the South Tower between the 78th and 84th floors, but sliced in at an angle, severely damaging the entire northeast corner of the building.4 Compared with the North Tower, the South Tower sustained damage that was both less evenly distributed and significantly lower on the building?s frame, requiring the weakened point to support more upper building weight than the corresponding crash site on the North Tower. This explains both the tilt of the building as it fell toward the weakened corner, and the fact that the South Tower fell first despite being struck after the North Tower was struck. Again, this scenario makes good sense if the buildings fell due to damage inflicted by the plane crashes, but makes very little sense if the buildings fell due to a planned demolition.
The 9/11 Truth Movement often states or implies that steel would have needed to melt in order for the structure to collapse at the speed of a free-fall. While there are varying assessments of the temperature of the fire at WTC, most agree that the temperature probably reached 1,000° Fahrenheit and possibly higher than 1,800° F. Flames of this temperature would be far short of the approximately 2800° F needed to melt steel, but they would have been sufficient to severely reduce the structural integrity of the metal. Best engineering estimates tell us that steel loses 50% of its strength at 650° F, and can lose as much as 90% of its strength at temperatures of 1,800° F.5 Even if we assume temperatures of no higher than 1,000° F during the fire, we would still have more than enough reasons to expect damage severe enough to result in eventual collapse.
The unique structure of the WTC towers exaggerated the problems caused by the weakened steel. The towers had a lightweight ?perimeter tube? design consisting of 244 exterior columns of 36 cm square steel box section on 100 cm centers, with 95% of the structure?s interior consisting of nothing but air (see Figure 1).6 Within this perimeter tube design there was a 27m by 40m core, designed to provide additional support to the tower. Steel trusses, or joists, connected the outer beams to the core at each story, and provided much of the overall support to the weight of each floor. The impact and explosion of the airplane crashes probably knocked off most of the insulating material intended to fireproof the steel beams, considerably increasing their vulnerability to flames. The heat of the flames reduced the steel to a fraction of its initial strength, while also causing the steel trusses to expand at each end until they no longer supported the weight of the building?s floors, triggering the collapse. The expansion and warping of the steel would have been particularly significant due to temperature differences within the burning structure.7 Thus, the trusses went limp much like a slackened laundry line, providing little or no resistance to the weight of the floors overhead. Figure 1. A cutaway diagram of the structure of the main towers at WTC
Figure 1 A cutaway diagram of the structure of the main towers at WTC
What about the ?melted steel? that 9/11 conspiracy theorists claim was at Ground Zero? Dr. Steven Jones? popular article cites several anecdotal sources speaking about flowing or pooled samples of melted steel found at Ground Zero.8 However, the sources in question are informal observations of ?steel? at Ground Zero, not laboratory results.9 To many people, any grayish metal looks sufficiently like steel to call it ?steel? when speaking informally. To actually establish that the substance in question is steel, we need analytical laboratory results using atomic absorption (AA) or another suitable test. It seems far more likely that the metal seen by the contractors was aluminum, a component of the WTC structural material that melts at a much lower temperature than steel and can look superficially similar to it. As for the ?squibs? conspiracy theorists claim to see in videos of the WTC collapse, these are plumes of smoke and debris ejected from the building due to the immense pressure associated with millions of tons of falling towers (see Figure 2). Videos of the WTC collapse show that these plumes do not begin until after the towers begin falling and increase in intensity as the collapse continues ? this is not the scenario one would expect if the plumes were actually explosives used to cause the buildings to fall. The Collapse of World Trade Center Building 7 Figure 2. circled area shows an alleged 'squib' (actually air compressed by the falling tower)
Figure 2 circled area shows an alleged ?squib? (actually air compressed by the falling tower)
?Not so fast,? the 9/11 Truth Movement might say. How do you explain the collapse of WTC Building 7, which was not struck by an airplane?
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