9/11 conspiracy theories


It may be 10 years since the attacks in the US on 11 September, but conspiracy theories have not faded over time, says Mike Rudin.

Numerous official reports have been published since the Twin Towers fell, but just when a piece of evidence casts doubt on one theory, the focus then shifts to the next "unanswered question".

Here are five of the most prominent 9/11 conspiracy theories circulating in online communities.

1. Failure to intercept the hijacked planes

The question: Why did the world's most powerful air force fail to intercept any of the four hijacked planes?

Conspiracy theorists say: The then US Vice President Dick Cheney ordered the military to stand down and not to intercept the planes.

File photo of a F-15 fighter Fighter jets failed to intercept the hijacked planes

Official reports say: This was a highly unusual multiple hijacking with violence on board, and where the transponder, which identifies the plane, was turned off or changed.

What is more, a routine military training exercise happened to be taking place that day at US air defence command.

Air traffic controller Colin Scoggins was in constant contact with the military and did not see any lack of response. There was confusion and a lack of communication between the civilian air traffic control (FAA) and the military.

The military's equipment was also outdated and designed to look out over the ocean to deal with a Cold War threat.

2. Collapse of the Twin Towers

The question: Why did the Twin Towers collapse so quickly, within their own footprint, after fires on a few floors that lasted only for an hour or two?

Conspiracy theorists say: The Twin Towers were destroyed by controlled demolitions. Theories relate to the rapid collapse (about 10 seconds), the relatively short-lived fires (56 minutes in World Trade Center 2 or 102 minutes in World Trade Center 1), reports of the sounds of explosions shortly before the collapse, and the violent ejections that could be seen at some windows many floors below the collapse.

Remains of World Trade Center buildings after the attacks on 11 September 2001 Five new skyscrapers are being built on the World Trade Center site

Official reports say: An extensive inquiry by the National Institute of Standards and Technology concluded that the planes severed and damaged support columns and dislodged fire-proofing.

Around 10,000 gallons of jet fuel were spewed over many floors starting widespread fires. Temperatures of up to 1,000C caused the floors to sag and the perimeter columns to bend, causing the sounds of "explosions".

The massive weight of the floors dropped, creating a dynamic load far in excess of what the columns were designed for. Debris was forced out of the windows as the floors above collapsed.

Controlled demolition is nearly always carried out from the bottom floors up, yet this collapse started at the top.

No evidence has ever been found of explosive charges despite the extensive hand searches and there is no evidence of any pre-cutting of columns or walls, which is routinely carried out in a controlled demolition.

3. Attack on the Pentagon

The question: How could an amateur pilot fly a commercial plane in a complicated manoeuvre and crash it into the headquarters of the world's most powerful military, 78 minutes after the first report of a possible hijack and leave no trace?

Part of the outer wall of the Pentagon collapsed after Flight 77 crashed into it A memorial in the grounds of the Pentagon marks the deaths of those who died when Flight 77 crashed

Conspiracy theorists say: A commercial Boeing 757 did not hit the building but instead a missile, a small aircraft or an unmanned drone was used. But since evidence has increasingly shown that the American Airlines Flight 77 did hit the building, the emphasis has shifted to questioning the difficult approach manoeuvre. It is argued it was not under the control of al-Qaeda but the Pentagon itself.

Official reports say: Airplane wreckage, including the black boxes, were recovered from the scene and they were catalogued by the FBI.

Although some early video did not show much wreckage, there is a good deal of video and still photography which shows plane wreckage and evidence of the flight path, such as broken lamp posts.

The remains of crew and passengers on the plane were found and positively identified by DNA. Witnesses also saw the plane strike the Pentagon.

4. The fourth plane - United Airlines flight 93

The question: Why was the crash site at Shanksville, Pennsylvania, so small and why was the aircraft debris not visible?

Conspiracy theorists argue: United Airlines flight 93 was shot down by a missile and disintegrated in mid air, scattering the wreckage over a large area.

The crash site of Flight 93 at Shanksville, Pennsylvania Forty-four people died when Flight 93 crashed in Shanksville, Pennsylvania

Official reports say: There are clear photographs showing aircraft wreckage and the cockpit voice recorder, which showed there had been a passenger revolt and the hijackers had deliberately crashed the plane.

Initial theories that heavy debris was scattered many miles from the main crash site turned out to be false. In fact the wind had blown light debris such as paper and insulation just over a mile.

Another theory was based on a misquote from the local coroner, Wally Miller, who said he stopped being a coroner after about 20 minutes because there were no bodies. What he also said was that he quickly realised it was a plane crash and there would have to be a large funeral service for the many victims.

In addition, the military never gave orders to the air force to shoot the commercial airliner down.

5. Collapse of World Trade Center Building 7

The question: How could a skyscraper, which was not hit by a plane, collapse so quickly and symmetrically, when no other steel-framed skyscraper has collapsed because of fire?

The remains of World Trade Center Building 7 Offices for civil emergencies, the CIA and the Secret Service were based in World Trade Center Building 7

Conspiracy theorists say: The World Trade Center Building 7 was destroyed by a controlled demolition using both explosives and incendiaries.

Initially the focus was on the phrase "pull it" used by the owner, Larry Silverstein, in a TV interview. But in fact he was talking about pulling firefighters back. (Demolition experts do not use the term "pull it" as slang for setting off explosives.)

Now the focus has shifted to the speed of the collapse which reached near free fall for 2.25 seconds. It is argued only explosives could make it collapse so quickly and symmetrically.

Some scientists, who are sceptical of the official account, have examined four dust samples from Ground Zero and claim to have found thermitic material which reacts violently when heated up. They claim tonnes of thermite and conventional explosives were rigged inside, not just WTC7, but also the Twin Towers.

Find out more

  • The Conspiracy Files: 9/11 - Ten Years On will be broadcast on Monday 29 August 2011 at 21:00 BST on BBC Two

Official reports say: A three-year investigation by the National Institute of Standards and Technology concluded that the building collapsed because of uncontrolled fires, started by the collapse of the nearby North Tower, and which burnt for seven hours.

The mains water feeding the emergency sprinkler system was severed. No evidence has ever been found of explosive charges and there are no recordings of a series of very loud explosions that would have been expected with controlled demolition.

Furthermore, there is an alternative explanation for the "thermitic material" the sceptical scientists found in the dust - it is just a type of primer paint. It's calculated 1,200,000 tonnes of building materials were pulverised at the World Trade Center and most minerals are present in the dust (not necessarily in a large quantity). More extensive sampling of the dust has not found any evidence of thermite or explosives, says a report from the US Geological Survey and another from RJ Lee.


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  • rate this

    Comment number 375.

    @Vik : You get the usa to PAY for an expensive investigation and another country will conduct one... or do you think 'yet another' american problem should be bought and paid for by foreigners?

    I think the usa has cost ~us~ enough this century...

  • rate this

    Comment number 374.

    With all this I still think this event is more recognised as 11/09.
    Nothing significant happened on 9th of November.
    That just sums up American arrogance, changing the universal date format.

  • rate this

    Comment number 373.

    Shadowplayer said: "it is physically impossible to fly a large jet aircraft along the alleged flight path into the Pentagon" (SHIELDS UP Mr. Sulu) WHAT ? (cue raucous laughter) The air around the Pentagon is different to anywhere else on Earth ?? WOW.. So how the heck do Aircraft manage to land at Ronnie Ray Gun's Washington National ?

  • rate this

    Comment number 372.

    Add your comment...See the way the BBC twists the facts.They say all the talk about 911 is "online communities".When in fact it goes far beyond.Eye witnesses including fireman,policeman who were caught up in explosionson the lower floors including the lobby.A caretaker of 20 years in WTC1 who heard explosions BEFORE THE PLANES HIT.And saw injured people as a result of th pre plane explosions.

  • rate this

    Comment number 371.

    Wow even the BBC, the BBC! That bastion of impartiality is covering the concepts expounded by the truth movement. Whatever next? Maybe one of those gutless supine BBC journalists will actually start reporting news instead of repeating lies fed to them as a condition of keeping their cosy little publicly funded jobs. And that includes you...ah who wrote this article?

  • Comment number 370.

    This comment was removed because the moderators found it broke the house rules. Explain.

  • rate this

    Comment number 369.

    One of the strangest things about this is that many of the 19 "hijackers" were found alive within weeks of the attacks. Considering their mugshots had been on every newspaper, saying they were responsible for these atrocities, how come there was next to no coverage about the mistaken identities? It's still buried in the BBC archive -


  • rate this

    Comment number 368.

    "Also the Pentagon is supposed to be missile proof so how come a fairly flimsy chunk of aluminium did all that damage?"
    So... if it was 'missile proof' it can't be a 'flimsy' missile that blew it up either... so the Loose Change guys are in on the conspiracy too! Good work? Aluminium burns like the booster rocket of a space shuttle, it will do a bit of damage if vaporised and ignited?

  • Comment number 367.

    This comment was removed because the moderators found it broke the house rules. Explain.

  • rate this

    Comment number 366.

    Given that we cannot rely ony any "official" explanation, the greatest evidence for an "inside job" is not so much the event itself, but what came out of it soon afterwards.

    Invasions and occupations of Afghanistan - still there after 10 years - Homeland Security, Patriot Act, ficitious "was on terror" and so on.

    9/11 was a means to further a covert agenda.

    Problem - Reaction - Solution.

  • rate this

    Comment number 365.

    Simple truth is the conspiracy nuts can't accept that the usa contains incompetents or ordinary people and that their nation doesn't use or have the super-fantastic technology & the decisive, heroic types that operate it as seen in the movies.

    As with Katrina & New Orleans, those that run the usa have feet of clay and magic hitech that solves all ills doesn't exist.

    Hijacked planes crashed!

  • rate this

    Comment number 364.

    All this bilge about Thermite, molten steel flowing at lower temperature than white hot, holographic masking of missiles as commercial aircraft etc. hides the real conspiracy that gave the New Yorkers a badly designed, badly built and poorly maintained building.

  • rate this

    Comment number 363.

    for all I poke fun at the CT, I do have one serious question. If the US Gov was involved by action or conspiricy of non prevention then would that not be self defeating as if it was ever proven it would totally destroy the very Gov system that instigated it?! So what is their reason?

  • rate this

    Comment number 362.

    There are lots of questions over the 9/11 attacks that do not seem to have been answered. The world view changed after these attacks, I for one do not see much value in these unproven theories. Conspiracy should look at the lead up to the attacks, like the pilot training of terroists and the police stopping and questioning and then releasing perpertators.

  • rate this

    Comment number 361.

    I'm no conspiracy nut, but one thing which has always alluded the press is the presence of 'nano-thermite' in the debris.

  • rate this

    Comment number 360.



    the point is there are people speaking out and the EVIDENCE is there!
    THE SPEED OF GRAVITY!ect...Show building 7 to any demolision expert whorth thier salt and they will tell you that what they are seeing is a controled demo....tell them its 911 and will they go on record and face the ridiqule that they are a C.T. NUT and then they may think of thier mortage first.

  • rate this

    Comment number 359.


    Oh look! a reasonable explanation for unburned pieces of paper?

    MUST be false!

    The Columbia Space Shuttle disaster: The craft broke up on re-entry, 40 miles about the earth, and debris fell over a wide area. Amongst this was one of the experiments involving tiny worms.

    Lifeforms survived a fiery fall from orbit? :o

  • rate this

    Comment number 358.

    All of the conspiracy theories surrounding 9/11 have been debunked countless times, yet people still continue to believe them. It's almost as if some people want the conspiracies to be true. You only need to go as far as conventional logic for the conspiracies to fall apart. How would the US government be able to cover such a huge thing up when they can't even cover up relatively little things?

  • rate this

    Comment number 357.


    Hi Harbinger,
    Even if the fires in 7 were hot enough, (which they weren`t), ALL 100 or so steel uprights would have to fail at precisely the same time.
    The fires were mainly on one side of the building, so it could not have fallen straight down.
    Even if the shock of 1 and 2 falling nearby had weakened all the steel, the chances of all of it failing at the same moment are nil.

  • rate this

    Comment number 356.

    Nick Nakorn - you haven't explained WTC7 freefall.
    Aborky - yes, air defences are designed to go after enemy aircraft which do not have "friendly" transponders on them!!! The hijackers switching off the transponders made the aircraft invisible to FAA but would be highlighted on DoD radars!


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