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9/11 Model Backs Up Tower Collapse Theory

Posted on Jun 20, 2007

A two-year study of the World Trade Center Towers’ collapse by Purdue University has reaffirmed the findings of the National Institute of Standards and Technology, which suggested that the buildings crashed under their own weight after crucial support columns and fireproofing were damaged or destroyed. The research team released an animation of the first plane’s collision to show how heat and flame eventually brought the towers down.

Watch the animation:

AP via Yahoo:

The two-year Purdue University study, funded in part by the National Science Foundation, was the first to use 3-D animation to provide visual context to the attacks, said Christoph Hoffmann, a professor of computer science and one of the lead researchers on the project.

“One thing it does point out ... is the absolute essential nature of fireproofing steel structures,” Hoffmann told the Associated Press. “This is something that wasn’t done originally in the World Trade Center when it was built. It wasn’t code at that time.”

Mete Sozen, a professor of structural engineering and a lead investigator on the simulation, said Purdue researchers hope their work leads to better structural design and building codes to prevent similar collapses.

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By s, June 20, 2007 at 1:43 pm Link to this comment
(Unregistered commenter)

It seems like WTC7 came down like the others did, but how was there a fire in it.  It was not between the two other towers but across the street from tower 1.  It was not connected to the concourse like the other building (1 through 6).  As far as the Bankers Trust Building was concerned (which was also across the street from tower 2, it was not really damage in the same way.  Most of the damage came from water damage, and mold.  The only building that I know of that was damaged from a building falling was a small church near tower 2.  So why did WTC7 come down?  It just seems strange that it fell like the other two which did have a big fire raging in them.

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By niloroth, June 20, 2007 at 1:35 pm Link to this comment

911truth guy:

own footprint?

nope, not even close.

Free fall speed?

Wrong again

Hit by nothing?  Even you can’t believe that one.

Stop lying.

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By Mekt_Ranzz, June 20, 2007 at 1:16 pm Link to this comment

I for one would like to know what exactly caused the squibs that appeared some 30 floors below the collapse wave of the north and south tower?

The 9/11 debunkers never really have a good answer for that question!

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By Alvin, June 20, 2007 at 12:59 pm Link to this comment
(Unregistered commenter)

This “study” is basically just a cartoon that rehashes old falsehoods. There is nothing approaching science in this thing; indeed, it is patent anti-science as it most studiously avoids all of the main weaknesses of the “official theory.”

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By Ken, June 20, 2007 at 12:54 pm Link to this comment
(Unregistered commenter)

This theory presented really does not add anything new other than a graphic illustration. It goes based on the assumption that the planes indeed did cause the collapse. However, little if any funding has gone to alternative theories or approaches. If you think about it, it would be quite scary to think any alternative. So the “official” theory has merits by technicality but so do the “truthers” given they do have indeed justified and legitimate questions that the Official Commission Report fails to address. Regardless, we are not getting the whole truth. There are just too many holes. And I have not got a clue as to how this happened!!! Because I cannot completely agree with the official report nor can I endorse the truthers, I say we have an new investigation. Into this matter. If you ever watched ‘9/11 Press for Truth’- the majority of the families who were directly impacted by the events on 9/11 have not had their questions answered. So in actuality they are keeping the movement strong.

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By 911truthdotorg, June 20, 2007 at 12:53 pm Link to this comment

Isn’t it very interesting how Purdue completely ignores WTC7 just like the sham 9/11 Commission did?
Like it never existed.

How convenient.

I wonder how many people in this country still have no idea that *3* buildings collapsed on 9/11.

WTC7 collapsed after being hit by nothing. At free fall speed. Perfectly in its own footprint.

Explain that Purdue!

Google videos: 9/11 Press for Truth, Loose Change 2nd Edition

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By KVE, June 20, 2007 at 12:22 pm Link to this comment
(Unregistered commenter)

I just want to note that the core columns as shown inthe simulation look nothing like the core columns you can see in construction photographs of the towers.  These photos are easily found and clearly show a series of 4’x4’, or bigger, core columns.  This does seem like a glaring flaw in the model.  Finally, what does it mean that this is a “two year” study from Purdue?  It could be any class project…I think another person did one on keg stands.

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By Jim Wright, June 20, 2007 at 12:19 pm Link to this comment
(Unregistered commenter)

To Verne Allen,

If you believe wood stands up to fire better than steel, you better get rid of the log grate in your fireplace.  I would suggest getting a wooden log grate and throwing some steel logs on the fire to get it roaring.  You are a joke

Question: Where did the molten steel under the collapsed buldings come from?  Was it a supernatural physics occurrence?

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By WarisPeace, June 20, 2007 at 12:18 pm Link to this comment
(Unregistered commenter)

Gravity does not allow a free fall in two actually three skyscrapers tower on tower two and building seven.

What ever happened it defied the law of gravity and only could have been accomplished with explosion of C2 the termite residue is good evidence.

Tell me how you can find a passport on top of all this rubble?

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By chucksheen, June 20, 2007 at 12:04 pm Link to this comment
(Unregistered commenter)

Don’t judge a book by it’s cover.

9/11 research deserves as much light as possible so please consider reading the following page for supplemental info regarding the Perdue models:

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By niloroth, June 20, 2007 at 11:08 am Link to this comment


More misinformation.  You again revert back to the whole “never before in history has fire brought down a skyscraper.”  Damaged building remember.  Your attempt to add the steel building bit simply means you failed to grasp my point.

How are there 2 buildings in between tower 7 and towers 1 and 2?  Again, half truths.  There are 2 buildings between tower 2 and WTC7, but one of them is tower 1.  But between tower 1 and WTC7 there is WTC 6.  What happend to WTC6, do you know?  The Bankers trust building was also damaged from the towers, do you know that?  Was that an inside job as well, or is that damage real?  If it is real, why can you accept damage there, but not at WTC7.

Who says it perfectly imploded?  Just because you, as someone who is not a demolitions expert does not understand how it imploded does not mean it was perfectly imploded.  This cuts to the heart of the issue, people have seen on tv buildings implode, then they see the towers go down, and it looks the same, to the untrained eye.  Ignorant people, and i mean that in the literal sense, then make judgments that are not backed up by fact, but it seems right.  The fact is that these judgments are wrong, and are being perpetuated for profit and gain by some people who should, or could if they wanted, know better. 

“Pull it” has never been used in demolitions as a way to express imploding a building.  However, pulling a team of firefighters, or soldiers, out of a bad situation is common.  I can’t tell you why he worded it that way, but it seems far more likely that he was talking about the fire fighter teams rather than the structure.  And even if he has no reasonable reason the have said that, are you telling me you would be making 100% sense while watching all that on tv and being personally effected?

Again, you are being used, by people pushing agendas, making names for themselves, or making money.  I personally would resent that, but thats just me.

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By Sam I am, June 20, 2007 at 11:03 am Link to this comment
(Unregistered commenter)

So the US government can pull off something like this??? I doubt it.  Was the Moon landing a hoax too?? Because if the government blew up the WTC, then I’m sure the moon landing was a hoax. And what about that Roswell thing?  Someone mentioned college kids uncovered that 9 of the supposed ‘hijackers’ were still alive? Really… and how would they do that?  What a load of crap….  And 2.3 Trillion in military materials ‘missing”. There has always been trillions of $$$ and materials missing, what does that have to do with anything?  Is someone insinuating that 2.3 trillion was used to blow up a building??  And after all the smoke and mirrors, our government couldn’t tell a lie and produce some fake weapons of mass destruction???  You Americans have some vivid imaginations and need to get a grip on reality. You may not know it, but your media is making you stupid; and they thrive of it.

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By Bill Blackolive, June 20, 2007 at 10:46 am Link to this comment
(Unregistered commenter)

Such caca.  The grade school yard, the prison yard, most humans are not far along enough to consider heroics, but will go along to not get beat up, will be told how to think, what to see or hear, be what is thought safe. Trouble here is too much hell to pay already.  Do we want freedom?  We do not have it. Enough folks must bear to think or we shall be stricken. We shall be in terror.  Shall we begin to think.

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By markloveshawaii, June 20, 2007 at 10:33 am Link to this comment


” This also brings a lie to your second contention, which is that fire has never brought down a skyscraper, since that is not really the case here is it?  Come on, be honest, your statement is really just bullshit isn’t it? “

Look in to this Fact, please do. You will find the closest to a skyscraper falling due to fire is a building in Austraila that the top 15 floors fell but nothing else, and thats after 23 hours of burning.  I should of included “no steal skycrapers” in the text if thats what your looking for. 

Yes and I know that no plane with tower 7 but why is there two buildings left standing inbetween towers 1 and 2   and the 7th tower?  does this make sense?  And how did it perfectly implode in on itself and why did Larry even say that they “pulled it”? 

And where is the missing 23 videos from local and goverment survailince showing the “plane” it the pentigon?

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By 7man, June 20, 2007 at 10:28 am Link to this comment
(Unregistered commenter)

It’s very clear to me that TruthDig only prints 9/11 articles and comments that shore up its pro-government postition. I have posted similar coments in the past but Truthdig never has posted them. As an architectural professional with 30 years of experience, controlled demolition is obvious, as is the post 9/11 coverup. There is little truth to dig here, so try where A/E professionals support a new investigation to the failure of the three structures on 9/11.

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By Jacob, June 20, 2007 at 10:25 am Link to this comment
(Unregistered commenter)

where’s the rest of the video? seems a bit incomplete. how does this lead to the building falling at freefall speed?


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By Hammo, June 20, 2007 at 10:23 am Link to this comment

It seems difficult to figure out which aspects of the 9/11 attacks seem to indicate that there might be more to them than meets the eye.

People who raise questions bring up quite a few different elements. Food for thought in the article:

“Viewpoints on 9/11 attacks span continuum of concerns”

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By markg8, June 20, 2007 at 10:18 am Link to this comment
(Unregistered commenter)

That fireproofing was a coating on the columns after the building was constructed? First I’d heard of that.

The thing I take away from this video is that at least one titanium engine shaft looked like it tumbled thru the structure like a dum dum bullet taking out anything in it’s path.

There’s definately a cover up but my guess it has a lot more to do with the fact that the building obviously was not built to withstand a direct hit by
a jetliner like the architects said it would and the utter incompetence of the Bush administration in failing to recognize the threat beforehand despite hundreds of warnings from at least 14 different allies.

On 9/11 Condi Rice was scheduled to make a major speech lambasting Dems for shifting $900 million from
Bush’s precious nat’l missile defense shield to anti-terrorism activities in the Defense bill a few days before. Needless to say that speech was never given and is now classified. Not because of any security considerations mind you - it was to be a public speech afterall - but because it’s embarrassing as hell and really points out just how unseriously they take national security. Why swat flies when you can give your buddies hundred billion dollar contracts to build weapon system boondoggles?

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By niloroth, June 20, 2007 at 10:09 am Link to this comment


The same old and discredited propaganda keeps on getting trotted out time and time again by people who are either to lazy to do the research to find the truth, or who are advancing a political agenda, or are simply interested in making money for themselves. 

I point out my last post.  WTC7 was not hit by a plane, it was hit by a building.  Why the staw man, and why not state the real truth? 

And don’t you think it is kinda funny that if loose change and the 9/11 truth movement is so sure of what happened, they keep changing their minds?  Multiple versions of the loose change video to cover up outright lies and mistakes they made.  911truth changes their story every time they are proven wrong.  They have no truth, just lies, straw men, and half truths.  I am sorry you got suckered, but stop trying to perpetuate your ignorance.

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By GB, June 20, 2007 at 9:59 am Link to this comment
(Unregistered commenter)

If anyone believes the government’s version of 911 completely I feel you don’t care about your country.
For three enormous structures to fall straight down into their footprint from a big hit in the side is impossible even to any novice thinking person.
This is the biggist crime in the history of the world and so many people are afraid to listen to the possibility that a government supported by corporate interests that lied to you to start a war in the middle east where thousands of innocent people have died and have used that excuse to strip the rights that were fought for over two centuries could possibly find innocent victims of a plan in New York merely an ends to a means.
All the big media voices against looking into this crime further stand to loose alot if the evidence turns against them.
What are you afraid of?

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By Chaseme, June 20, 2007 at 9:56 am Link to this comment
(Unregistered commenter)

There is usually a problem when one attempt to cover up for a lie or lies. It often times (excuse the pun) punch a hole in the other lie or lies.

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By Frikken Kids, June 20, 2007 at 9:45 am Link to this comment

Hey, Jacks, I think it’s quite a reach to call me a bigot because I linked to The Best Page in the Universe.  I’m not a huge Maddox fan, but most of what he writes can be called, at worst, politically incorrect. 

The page directly linked to comically tears to shreds all the conspiracy bullshit.  Please explain the bigotry in that page or how I am a bigot for posting a link.

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By Jacks, June 20, 2007 at 9:34 am Link to this comment

I can only imagine how heartbreaking it must be for the families of the victims to see that image repeated ad nausea, let alone listen to the self-serving conspiracy theorists.

The bigot who linked to the Best Page in the Universe: what the hell?!  What next?  Linking to a David Duke comic on current affairs.

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By PaulMagillSmith, June 20, 2007 at 9:26 am Link to this comment

This study is not very convincing when compared to other issues like:

Tuesday, May 16 2006

The best place to start is to “follow the money”. Who stood to gain? Who actually gained financially? What happened to the records of hundreds of cases of insider trading that disappeared when WTC#7 very mysteriously collapsed, never even hit by a plane that day? Where did the rest of the billions in gold & silver bullion go that was under the WTC buildings go? Why wasn’t more mention made of the $2.3 Trillion in military materials ‘missing’ that was disclosed the day prior to 911? The WTC towers were slated for demolition anyway, at the cost of as much as $10+ billion, so why would someone even want to buy them? and insure them? and less than a year before the attacks? Why didn’t the investigations begin immediately, and why did the Bush administration do everything it could to delay & block the investigation? If two students in a $6000 movie (Loose Change:2nd Edition) could uncover that 9 of the supposed ‘hijackers’ were still alive, why haven’t we heard about this from the government and in the main stream media?

There are literally millions of people demanding a complete, comprehensive, unbiased re-examination of the events of 9/11 and before, yet all we get is the sham known as The Official 911 Commission Report.

After the bloodbath America &  other countries have suffered in the days since 911 we deserve to know the truth…no, we DEMAND to have our questions answered, and a study of computer generated models just doesn’t cut it!!!

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By Godon Soderberg, June 20, 2007 at 9:14 am Link to this comment
(Unregistered commenter)

I don’t see anywhere in truthdig or anywhere else on the Internet that Jews were blamed in general or otherwise for 911. Mussad has been, and I tend to agree that it is more likely that Mussad had a hand in 911 than OBL. That is not to say Jews did it. I don’t blame all whites for the creation of the KKK, the herritage institute or PNAC.

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By randy paugh, June 20, 2007 at 9:11 am Link to this comment
(Unregistered commenter)

what other building hit wtc7?

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By STEVE, June 20, 2007 at 9:10 am Link to this comment
(Unregistered commenter)

So some guys at Purdue got some grant money and made a cartoon…..

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By Tom Doff, June 20, 2007 at 8:50 am Link to this comment
(Unregistered commenter)

I didn’t even know we needed a ‘Tower Collapse Theory’.

I though they collapsed because a group of Saudis got pissed at the way arabs have been treated by the US and Israel for decades, and finding that they had no means of recourse other than violence, decided to fly a couple of planes into the buildings to draw attention to their plight, and not-so-incidentally, destroy a US landmark that was a symbol of the financial hegemony which was harming the muslim world, and a bunch of zionists who were pulling the strings of the hegemony on a day-to-day basis.

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By niloroth, June 20, 2007 at 8:34 am Link to this comment


I realize that if you still a 9/11 conspiracy after all this time, nothing i say will convince you, but quite frankly the WTC7 issue has been dealt with well enough.  And here is the way most of you people look at things.

“Fine and dandy the computer makes a decision weather or not a building falls down but what about building 7 there was no plane that hit it and fire has NEVER in the history of the world brought down a skyscraper.”

Now, that statment seems fine, untill you realize that while no plane hit WTC7, another building did, so your statment about the plane is misdirection, i am guessing you either havn’t thought of that yourself, or have misrepresented the information intentionaly.  This also brings a lie to your second contention, which is that fire has never brought down a skyscraper, since that is not really the case here is it?  Come on, be honest, your statement is really just bullshit isn’t it?

The sad thing is, that a bunch of liars and assholes with political agendas have forced us to have to be debating this years after the fact.  these people are like young earth creationists, irrational, antiscience, and antireason.  Why be a tool of these people Mark?

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By Dr. Knowitall, PhD, PhD, June 20, 2007 at 8:26 am Link to this comment

The fact remains this was an earth-shaking event, it happened, there’s no more WTC, thousands of lives were lost and/or changed, it’s fallout will go on for decades and the LEADER of the free world sat on his ASS for several minutes after he was told HIS country was UNDER ATTACK and then, he proceded to manufacture a “war on terror” and occupy a country whose leader and citizens had absolutely nothing to do with the WTC destruction, we re-elected him, the “war on terror” is still going on four years later and getting worse.  I don’t much care, at this point, about the science of planes being flown into buildings and how they collapse.  I do care that the extremeists probably bellowed “Great is Allah” as the plane hit and the death toll which was three or four thousand then has grown to probably hundreds of thousands and rising.  The science here shows remarkable technical progress, progress which will do NOTHING to help civilization endure because we can’t make progress in abolishing greed and hate.

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By Chaseme, June 20, 2007 at 8:18 am Link to this comment
(Unregistered commenter)

Who paid Purdue for this “visualization research”?

I don’t buy any of it, because it only confirms my theory about what exploded into the Pentagon and I thank you for that.

This research shows clearly the impact of the wings of this aircraft and the impact and damage those wings caused. Why did we see such a perfectly oval formed in the side of the Pentagon, with no sign of wing damage?

This animation clearly shows that the wings could cause extensive damage, along with the hundreds of gallons of fuel they hold. There was enough fuel, considering they were topped off prior to take-off, to create enough heat to weaken the steel beams to bring down the WTCs.

Okay, what happened to those wings and all of that fuel at the Pentagon?

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By Jimmy, June 20, 2007 at 8:09 am Link to this comment
(Unregistered commenter)

Well this confirms it for me now .... Truthdig is another gatekeeper site. What a bull crap hit piece of garbage. Just in time for what has just been disclosed by a WTC7 security official who says bombs were going off in building 7 before the towers even collapsed.
9/11 Bombshell: WTC7 Security Official Details Explosions Inside Building

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By Frikken Kids, June 20, 2007 at 8:07 am Link to this comment

Steve Hammons,

Citing the opinions of a majority of Americans is really a poor argument.  The majority of Americans believe that the earth was created in its present form less than 6000 years ago.  It wasn’t too long ago that pretty much everybody on the planet believed the earth was flat.  If a lot of people believe a foolish thing, it is still a foolish thing.

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By James Yell, June 20, 2007 at 7:44 am Link to this comment
(Unregistered commenter)

I always felt that the explainations for the collapse of the buildings made sense. It was a combination of the weight above being lifted, causing recoil of the whole structure, leading to the complete failure of the entire structure. Indeed it was like the controlled collapse of demolition. This represented a design flaw in the building, which was not as I understood it built in traditional pattern. It was in some ways like a tent.

As to who did this, I believe that even though I have nothing but disdain for the dual criminals Bush/Cheney, they did not do this. It is too well documented that the Moslems highjacked and flew the planes into the buildings. Planes loaded with fuel and at the beginning of their travel are wonderful bombs.

This doesn’t of course answer the question about why law enforcement ignored intellegence data showing something was in the works. It doesn’t excuse the Bush/Cheney administration focusing on raiding the US treasury, rather than tending to business. There is still a question did Isreal know something about what was planned by the Moslems?

The creation of Homeland Security is just a device to further cloud law-enforcement and intellegence work. Another way to hide incompetence. People make fun of old sayings, but I think in regards to Homeland Security we should remember the old saying, “don’t put all your eggs in one basket”. People who like being in control like the idea of monopoly in power, because it pumps up the amount of income they can expect, massages their egos, but it decreases the numbers of trained leaders and takes away real accountability. That is one of many reasons why dictatorships are a bad idea and the coming Christian Fundamentalist Dictatorship is as bad as any Islamic mean spirited theocracy.

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By Hammo, June 20, 2007 at 7:22 am Link to this comment

Apart from the collapse of these buildings, there are other questions about the circumstances of 9/11.

Take a look at:

“Poll results on 9/11 attacks show many Americans have suspicions”

-  -  -

“Questions about 9/11 attacks include wide range of factors”

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By randy paugh, June 20, 2007 at 7:16 am Link to this comment
(Unregistered commenter)

I will give you the benefit of the doubt on wtc1 & wtc2….please convince me on WTC7!!

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By Christopher Robin, June 20, 2007 at 7:13 am Link to this comment
(Unregistered commenter)

I’m surprised it required a two year study to conclude this? (taxpayer funded I suppose?)

Structural damage aside, fireproofing sprayed on beams is not impact resistant, once it’s knocked off the steel, those areas become exposed to the full temperature of the fire.

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By markloveshawaii, June 20, 2007 at 7:03 am Link to this comment

Fine and dandy the computer makes a decision weather or not a building falls down but what about building 7 there was no plane that hit it and fire has NEVER in the history of the world brought down a skyscraper.  Wheres the computer rundown for that?  And how did it fall perfectly? If fire caused that than controlled demolition experts would use fire unstead of many months of preperation and lots of expensive c4!  Lets face it USA blew the towerS up!!!!!

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By Verne Arnold, June 20, 2007 at 6:52 am Link to this comment

As a manufacturing engineer I have never doubted the fact of structural failure due to impact and more importantly heat from the burning fuel…these planes were full, having just been refueled before take-off.

When, many years ago (I was a teenager), I worked for Nissan motors, they built an addition to the warehouse I worked in.  The supporting posts were wood.  I was surprised and asked the head of construction why.  He told me that if there is a fire the wood will hold up the roof longer than steel posts…when the steel posts hit 900 degrees they will begin to fail…at about 1000 degrees they will fail.  The wood posts will hold until they are almost burned through.

Any amateur engineer will know this.

All this other “stuff” about controlled demolition is pure fantasy. 

The present administration may be complicit, but, it’s because of gross negligence, not conspiracy.

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By Frikken Kids, June 20, 2007 at 6:05 am Link to this comment

I still think the best refutation of the conspiracy theories can be found at

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By alan, June 20, 2007 at 6:03 am Link to this comment

I think this study is correct. I do think, however that this administration had warning after warning that something was up and they did nothing to stop it.

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By lilmamzer, June 20, 2007 at 5:24 am Link to this comment

These findings will not stop the typical Truthdig conspiracy theorists from blaming Bush, the US Government, the CIA, Israel, the Mossad, and Jews in general, for these attacks. 

Truthdig would do well to remember Occam’s Razor.

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