Editor’s note: This story includes content and information around the events of Sept. 11, 2001, and may be distressing to some viewers.
On Sept. 11, 2001, suicide bombers linked to terrorist group al-Qaida hijacked commercial passenger planes, crashing two of them into the World Trade Center’s Twin Towers in New York City. Another plane hit the Pentagon and a fourth plane crashed in a field in Shanksville, Pennsylvania. In total, 2,977 people were killed in the 9/11 attacks.
After 9/11, then-President George W. Bush vowed revenge against the terrorists responsible. In 2011, former President Barack Obama announced Osama Bin Laden, a founder of al-Qaida and the architect of the Sept. 11 attacks, was killed during a targeted operation against his compound in Abbottabad, Pakistan.
Also in 2011, the 9/11 Memorial was opened to the public at the former World Trade Center site. The focal points of the memorial are two pools, which have the names of those who died engraved into the basins. The 9/11 Memorial Museum houses “an unparalleled repository consisting of material evidence, primary testimony, and historical records” about the attacks.
Conspiracy theories quickly emerged following the 9/11 attacks and they are still shared across the internet to this day, despite the existence of the full and complete account of the circumstances surrounding the Sept. 11, 2001, terrorist attacks. That account was published in a 600-page report called The National Commission on Terrorist Attacks Upon the United States, also known as the 9/11 Commission. The commission closed in 2004, after publishing its findings.
Christopher Kojm, the deputy director of the 9/11 Commission, said the commission was established by Congress “to determine the facts and circumstances of the 9/11 attacks, and to make recommendations to make the country safer.”
The VERIFY team researched two popular conspiracies connected to the collapse, one on how the buildings fell, and the other on how hot jet fuel needs to be to damage steel.
THE QUESTION
Did commercial jet planes cause both towers to collapse?
Source of conspiracy theory: Controlled demolition theories claiming explosives were planted at the Twin Towers prior to the planes’ impact have circulated online for years.
THE SOURCES
THE ANSWER
Yes, the planes caused the collapse of the towers. A summary from NIST said investigators found no evidence the towers were brought down using explosives. When the planes crashed into the buildings, the impact and subsequent fires from jet fuel weakened the buildings, which led to their eventual collapse, the summary said.
WHAT WE FOUND
Roughly 200 technical experts reviewed “tens of thousands of documents, interviewed more than 1,000 people, reviewed 7,000 segments of video footage and 7,000 photographs, analyzed 236 pieces of steel from the wreckage, performed laboratory tests, and created sophisticated computer simulations of the sequence of events that occurred from the moment the aircraft struck the towers until they began to collapse,” the NIST report said. Based on the gathered data, investigators found no evidence of explosives at the World Trade Center site.
Kojm told VERIFY “there is evidence in every direction that planes crashed into buildings.” He said the planes took off, passengers and pilots communicated from those planes and the “wreckage from planes was present at every crash site.”
According to a 2005 public briefing from the National Institute of Standards and Technology (NIST), American Airlines Flight 11 hit the north face of North Tower 1 (1 WTC) at 8:46 a.m., and it collapsed after 102 minutes. At 9:02 a.m United Airlines Flight 175 crashed into the South Tower (2 WTC) and the building fell after 56 minutes.
“The tragic consequences of the September 11, 2001, attacks were directly attributable to the fact that terrorists flew large jet-fuel laden commercial airliners into the WTC towers,” the briefing said.
“Buildings for use by the general population are not designed to withstand aircraft attacks; building codes do not require building designs to consider aircraft impact,” the briefing said. “In our cities, there has been no experience with a disaster of such magnitude, nor has there been any in which the total collapse of a high-rise building occurred so rapidly and with little warning,” it said.
A computer simulation posted to YouTube from the Smithsonian Channel explains how the towers fell.
At an Aug. 21, 2008, media briefing, Shyam Sunder, lead investigator with NIST, said: “Before I tell you what we found, I’d like to tell you what we did not find. We did not find any evidence that explosives were used to bring the building down.”
A summary from NIST said investigators “found no corroborating evidence for alternative hypotheses suggesting that the WTC towers were brought down by controlled demolition using explosives. NIST also did not find any evidence that missiles were fired at or hit the towers. Instead, photographs and videos from several angles clearly show that the collapse initiated at the fire and impact floors and that the collapse progressed from the initiating floors downward until the dust clouds obscured the view.”
THE QUESTION
Does jet fuel burn hot enough to melt steel?
Source of conspiracy theory: The phrase “jet fuel can’t melt steel” has circulated online since Sept. 11, and even became part of popular meme culture. The BBC was one media outlet that quoted a structural engineer who said the tower's columns would have melted in the fires caused when the planes crashed.
The claims resurfaced recently when Spike Lee was interviewed by the New York Times about his new documentary called “NYC Epicenters 9/11-2021 ½.” He was asked about interviewing conspiracy theorists for the documentary, and if he “buys official explanations” into why and how the buildings collapsed.
Lee said: “The amount of heat that it takes to make steel melt, that temperature’s not reached.”
Lee has since reportedly cut the conspiracy-related scenes from the final chapter of the documentary.
THE SOURCES
THE ANSWER
While it’s false that jet fuel does not burn hot enough to melt steel, jet fuel does burn hot enough to damage steel. On Sept. 11, the jet fuel was hot enough to bend steel and contribute to the buildings’ collapse.
The National Institute of Standards and Technology (NIST) reported the jet-fuel-ignited multi-floor fires, which reached temperatures as high as 1,800 degrees Fahrenheit, “significantly weakened” the buildings’ structures.
WHAT WE FOUND
According to Brian Kross, the chief detector engineer with the Thomas Jefferson National Accelerator Facility (Jefferson Lab): “Many sites refer to the difference in the melting point of steel and the burning temperature of jet fuel as proof that the World Trade Center could not have fallen from the aircraft fires. What those authors fail to note is that while steel melts at around 1,370°C (2500°F) it begins to lose its strength at a much lower temperature.”
“The steel structure of the World Trade Center would not have to melt in order for the buildings to lose their structural integrity. Steel can be soft at 538°C (1,000°F) well below the burning temperature of jet fuel,” Kross wrote.
Thomas Eagar, a professor with the Massachusetts Institute of Technology, told VERIFY when steel reaches between 1,100 and 1,200 degrees Fahrenheit, it loses half its strength.
The National Institute of Standards and Technology (NIST) analyzed hundreds of steel components from the towers as part of their final report, published in 2015. Congress asked NIST to conduct a technical investigation into the buildings’ collapse.
According to the final report: “Following the impact of the aircraft, the jet-fuel-ignited fires created the sustained and elevated temperatures that heated the remaining building structure to the point of collapse initiation.”
“Based on its comprehensive investigation, NIST concluded that the WTC towers collapsed because: (1) the impact of the planes severed and damaged support columns, dislodged fireproofing insulation coating the steel floor trusses and steel columns, and widely dispersed jet fuel over multiple floors,” an explainer from NIST outlined.
“And (2) the subsequent unusually large number of jet-fuel ignited multi-floor fires (which reached temperatures as high as 1,000 degrees Celsius, or 1,800 degrees Fahrenheit) significantly weakened the floors and columns with dislodged fireproofing to the point where floors sagged and pulled inward on the perimeter columns. This led to the inward bowing of the perimeter columns and failure of the south face of WTC 1 and the east face of WTC 2, initiating the collapse of each of the towers. Both photographic and video evidence—as well as accounts from the New York City Police Department aviation unit during a half-hour period prior to collapse—support this sequence for each tower,” it said.
“It's just not as strong when it is hot, we know that from a blacksmith taking his hammer to forge something. When it's red hot, he can beat it with a hammer, and it will deform and bend,” Eagar told VERIFY.
Trenton Tye, a Georgia-based blacksmith who has been featured on the History channel, posted a video to YouTube in 2015 that racked up more than 11 million views, to debunk what he called the “moronic jet fuel argument.”
“I am not arguing the facts, jet fuel does in fact burn at 1,500 degrees, steel will start melting, some carbon steels, at 2,300 degrees but if you hold this up as a reason for conspiracy, you are an idiot,” Tye says in the video, holding a ½-inch thick piece of structural steel.
Tye puts the steel in a 250-pound anvil, then shows how the steel supports the anvil. He then shows what an identical piece of steel looks like when he pulls it out of a furnace he says is burning at 1,800 degrees. The steel bent but did not melt.
“It’s a freaking noodle, your argument is invalid,” he says.
So, we can VERIFY that burning jet fuel can't melt steel, but it did damage it and contribute to the collapse of the towers.
THE QUESTION
Did a plane actually hit the Pentagon on Sept. 11?
Source of the conspiracy: Claims a missile hit the Pentagon, instead of American Airlines Flight 77, have also circulated online for years. Many of the claims stem from a video clip claiming Tim Roemer, a former member of Congress and head of the 9/11 Commission, misspoke during an interview and said a missile hit the building. The videos have gotten thousands of views across several platforms, including YouTube and BitChute, a video hosting platform.
THE SOURCES
THE ANSWER
Yes, documents citing witnesses, photo evidence and video footage from the Department of Defense show American Airlines Flight 77 did strike the Pentagon.
WHAT WE FOUND
Video footage released on Sept. 8, 2016 by the Department of Defense shows an animation, with radio traffic, of American Airlines Flight 77’s path and impact on the Pentagon on Sept. 11. At 43 seconds into the video, the Pentagon’s west wall bursts into flames.
Warning: Graphic content
Witnesses also described the plane hitting the Pentagon in official documents.
“Others in the immediate vicinity who witnessed the impact recalled that the airliner struck several obstacles, including light poles on Route 27, on the way to its target. The right wing hit a portable generator and the right engine crushed a chain link fence. The left engine smashed an external steam vault. Observers saw debris falling from the plane and the building. Five images from a Pentagon security camera, approximately a second apart, recorded the approach, the crash, and the immediate effect-a huge fireball,” a document titled “Pentagon 9/11” from the Historical Office from the Office of the Secretary of Defense said.
The Federal Bureau of Investigation released videos and photos from the crash site. Photos show crushed metal from the American Airlines plane.
WHY 9/11 CONSPIRACIES PERSIST
Christopher Kojm, the deputy director of the 9/11 Commission, said he thinks despite a two-decade gap since the attacks, people still have questions about the attack.
Kojm said “conspiracy theories provide explanations” and people want explanations during times of upheaval and “conspiracy theories provide explanations.”
“9/11 was a great upheaval and shattered people's expectations and norms of safety, security. And people felt powerless. And psychologically, people look for explanations as to why they are powerless and run in the direction of: that powerful individuals or governments or organizations were responsible for these acts,” Kojm said.
“And when people live in the midst of upheaval, they try to give order and certainty to their lives and conspiracy theories provide explanations. And those who propound conspiracy theories also are in the psychological state of ‘Well, I know the real truth, and I know better than you and so listen to what I have to say.’”
Karen Douglas, a professor of social psychology at the University of Kent in the United Kingdom has been studying the psychology of conspiracy theories for over 10 years. Douglas said, “when something major like this [9/11] happens, people are scared and uncertain and are looking for ways to cope with these feelings. Indeed, conspiracy theories do seem to thrive in times of crisis when people are looking for explanations and trying to find ways to feel better.”
University of Miami Professor of Political Science Joseph Uscinski has been studying conspiracy theories and the people who believe them for more than a decade. He also co-authored the book American Conspiracy Theories.
Uscinski told VERIFY a conspiracy theory “is an idea positing that a small group of usually powerful people benefits, against the common good.”
“Conspiracy-minded people focus on big events, just like everyone else, and turn their ire towards those events,” he said.
The VERIFY team works to separate fact from fiction so that you can understand what is true and false. Please consider subscribing to our daily newsletter, text alerts and our YouTube channel. You can also follow us on Snapchat, Instagram, Facebook and TikTok. Learn More »