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A NYPD car covered in debris and ash, following the 9/11 terrorist attacks

The biggest 9/11 conspiracy theories debunked

Out of the ashes of this atrocity arose several conspiracy theories.

Image: Anthony Correia /

It was the deadliest terrorist attack in the history of the United States. On September 11th 2001, American Airlines Flight 11 and United Airlines 175 smashed into the North and South towers of the World Trade Center in New York City. Just over an hour and forty minutes later, both towers had collapsed. In Washington DC, American Airlines Flight 77 was flown into the side of the Pentagon, collapsing a significant section of the building’s west wall. Finally, in Pennsylvania, United Airlines Flight 93 crashed into a field near the town of Shanksville after passengers on board overpowered the plane’s hijackers. In total, 2,996 died that day. Many more have died in the years since.

Out of the ashes of this atrocity arose several conspiracy theories. Some of them were so fanciful that they were easy to debunk. Others have proven much harder for the authorities to shake off. Here we present some of the more persistent conspiracy theories surrounding the events of that fateful day, as well as the most plausible explanations put forward by experts, official reports and eyewitnesses.

The World Trade Center attacks

The planes couldn’t have caused that much damage

One of the most persistent claims made by sceptics is that the two planes that hit the North and South towers could not have possibly caused so much damage to the floors below impact. The first jet hit the North Tower between the 98th and 94th floors; the second jet hit the South Tower between the 84th and 78th floors. Despite the height of both impacts, eyewitnesses reported seeing damage to both lobbies of the Twin Towers. How can that be possible? Surely a more plausible explanation is that secondary explosives were set off further down the towers, thus causing damage to the lower floors and both lobbies.

The melting point of steel is 1510°C. The temperature at which jet fuel burns is between 426.6°C and 815.5°C...

The official National Institute of Standards and Technology (NIST) investigation into the towers’ collapse found that the planes had caused considerable damage to both buildings’ utility shaft systems as they sliced through the towers. This allowed jet fuel to pour down elevator shafts. The fuel ignited, leading to raging fires gushing down the shafts. Many elevator cables were cut and braking systems disabled on impact, causing elevators to crash to the ground, smashing open lobby doors on impact and sending jets of burning fuel into both lobbies. These explosive jets caused considerable damage and set many people on fire - something witnessed by Jules Naudet, a cameraman who was one of the first on the scene in the lobby of the North Tower shortly after the impact of Flight 11.

Burning jet fuel cannot melt steel

The melting point of steel is 1510°C. The temperature at which jet fuel burns is between 426.6°C and 815.5°C. So how could the towers collapse due to structural failure when the fires were not hot enough to melt steel?

While it is indeed true that burning jet fuel alone cannot melt steel, a fire that was also fueled by burning furniture, curtains, blinds, chairs, desks, computer equipment and an enormous amount of paper would have burned hot enough to warp steel. NIST estimates that the fires in the towers reached at least 1000°C in certain pockets. The point at which steel weakens is 593.3°C, at which point it will have lost about 50% of its strength. Heated to 1000°C, steel will have lost about 90% strength. It was this weakness in the steel that led to the loss of the buildings’ integrity. As the steel warped and buckled, the columns and steel beams holding the towers up were no longer able to support the weight of the buildings, leading to the pancake collapse of both towers.

The towers were brought down by controlled demolition

Many sceptics point to film of mysterious puffs of smoke emanating from each of the floors of the towers as they collapsed. These puffs of smoke are seen as proof that the building was brought down by the setting off of explosives that had been drilled into the columns of the towers prior to the 9/11 attacks.

There are two problems with this theory. Firstly, no credible report has ever emerged of demolition teams being spotted drilling holes in the columns of a busy office complex in the weeks prior to 9/11. Surely somebody on at least one floor would have noticed something? Secondly, the Twin Towers contained enormous quantities of air. As each floor gave way and collapsed down on the one below, that air was instantaneously compressed and had to go somewhere. While it may look like a series of small explosions occurred as the buildings collapsed, what was actually happening was the air - mixed with tonnes of instantly-pulverized concrete - was expelled outwards as each floor collapsed, thus giving the impression of detonation.

The mystery of Tower 7

World Trade Center 7 was a 47-storey skyscraper that collapsed hours after the Twin Towers fell. When WTC 7 collapsed, it looked to many – including experts observing on the day - that the building had been brought down by controlled demolition. This, according to sceptics, is further evidence that 9/11 was an inside job.

While it may indeed look like WTC 7 was brought done by controlled demolition, this explanation does not take into account what happened to it in the immediate aftermath of the attack and in the hours that followed.

As the North Tower collapsed, considerable amounts of debris smashed into the south face of WTC 7, effectively scooping out 25% of the building from the ground to the tenth floor, thus massively weakening the building’s structural integrity. Multiple fires also started as a result of the collapse. One, on the fifth floor, raged for seven solid hours. It was only a matter of time before the structural damage caused by the North Tower’s collapse added to steel weakened by hours and hours of fire brought the building down. That the building’s collapse looked suspiciously like a controlled demolition can be explained by the fact that with the middle of the building severely compromised, first the east and then the west sides of the building collapsed in on themselves before pancaking to the ground, thus giving off the impression of a controlled demolition of the type often seen on the news and YouTube

The Pentagon attack

How can a 125ft plane cause just a 16ft wide hole?

A Boeing 757 commercial airliner is 125ft wide and 155ft long. However, the plane that smashed into the Pentagon left an entry hole just 16ft across and an exit hole of just 12ft wide. How is this possible, ask sceptics? As far as many people are concerned, it is more likely that the Pentagon was hit by a satellite-guided missile controlled by the US military

The official ASCE Pentagon Building Performance Report estimates that the hole punched into the outer E-Ring of the Pentagon’s reinforced concrete walls was actually about 75ft across, not 16ft, as has been widely misreported. That Flight 77 didn’t leave a 125ft, plane-shaped hole in the building is accounted for by the fact that one of the plane’s wings disintegrated when it hit the ground before impact and the other wing sheared off on impact, being of too lightweight a construction to penetrate reinforced concrete. The C-ring impact exit hole was, in fact, 12ft wide, not 16ft, and was most likely caused by the aircraft’s much sturdier landing gear punching its way through the building.

Where’s the debris?

Many point to the lack of debris in official photos taken after the plane hit the side of the Pentagon. When planes crash, they usually leave behind huge quantities of debris. How come a large commercial airliner hit a building yet left hardly any wreckage behind?

Most of Flight 77 ended up inside the Pentagon, not outside it.

This claim is directly disputed by eyewitnesses who were first to respond. This includes Allyn E. Kilsheimer, CEO of KCE Structural Engineers PC in Washington. Kilsheimer was the man who found Flight 77’s black box recorder, as well as holding sections of the plane’s tail in his hands and observing a wing impact mark on the side of the building before a large section of the Pentagon’s outer wall collapsed. He also saw bits of body parts scattered around the crash site, as well as crew uniforms and passenger clothing. Also, most of Flight 77 ended up inside the Pentagon, not outside it.

Flight 93

Was flight 93 brought down by a jet fighter?

A small white aircraft witnessed flying over the Flight 93 crash site shortly after the plane crashed has led many people to believe the airliner was deliberately shot down by this mysterious plane, which was, in fact, a US Air Force fighter jet.

While it was indeed the case that several eyewitnesses saw a white plane very shortly after Flight 93 went down, it was a Dassault Falcon 20 private jet operated by a North Carolina company called VF Corp. The plane was already making its descent into Johnstown-Cambria Airport when it was asked by the Federal Aviation Administration’s Cleveland Center to investigate the area shortly after Flight 93 crashed outside of Shanksville. The Falcon 20 duly did so, descending from 3,000-4,000ft to about 1,500ft where it spotted a large hole in the ground and a large amount of smoke. After reporting its finding to the FAA, the plane landed at the airport as planned.

Debris at Indian Lake

If Flight 93 crashed into the ground outside Shanksville, PA, why were debris and human remains seen floating in Indian Lake some six miles away from the crash site? This proves the plane was already breaking apart before it crash-landed, most likely after being hit by a missile.

It has never been proven that human remains were found in Indian Lake. It is indeed true that light debris such as scraps of metal and paper were found in the lake, this can be explained by the fact that the lake is actually just 1.5 miles away from the crash site, and that the 9-12mph northeast winds of that day could easily have deposited light debris in the lake after being blasted high into the air by the impact.

Despite years of analysis and investigation, several enquiries and the publication of both official and non-official reports, no amount of evidence will ever be enough to convince some people that the attacks on September 11th 2001 were not an inside job. While it is easy to dismiss people’s questioning of the events of that day as the ramblings of cranks and crackpots, the very fact that these conspiracies persist nearly twenty years later is a testament to the mistrust many people in the USA hold against their own government. The fact they are willing to believe their government is capable of carrying out such an atrocity is a troubling thought indeed.

For more articles about 9/11, check out our September 11th attacks hub