Explainer: What happened on September 11, 2001?

  • The terrorist attacks on the World Trade Centre in New York City killed thousands of people and lead to wars in Afghanistan and Iraq
  • Here’s a brief summary of what happened on the day, as well as its lasting impact on politics and the world
Dannie Aildasani |

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Smoke rises from the destroyed World Trade Centre in New York City on 15 September 2001, four days after terrorists flew two planes into the buildings, killing thousands. A third plane targeted the Pentagon and a fourth plane heading towards Washington, DC ultimately crashed into a field. Photo: EPA-EFE

It has been more than 20 years since the September 11 attacks. We understand that many Young Post readers were not yet born when the attacks happened, and even if you know a little bit about the event, you might be confused about some of the details.

For many people who were alive in 2001, that day was life-changing and scary, and we’re still seeing the effects of these attacks two decades later. Politics in the US took a sharp change, and countless numbers of innocent people were killed in the wars in Afghanistan and Iraq that came after the attacks.

Here’s a basic explanation of what happened on that day – but do note that the story is a lot longer and more complex than what we can express in one short article.

People look out of the burning North tower of the World Trade Centre in New York City on September 11, 2001. Photo: Reuters

What happened on 9/11?

On September 11, 2001, a series of four coordinated terrorist attacks took place in the US. A militant Islamic terrorist group called al-Qaeda hijacked four aeroplanes. One plane was flown into the North Tower of the World Trade Centre in New York City at 8:46am. At 9:03am, a second plane hit the South Tower. Both of the 110-storey skyscrapers collapsed within an hour and 42 minutes, and the force of it impacted other buildings nearby and caused them to fall as well.

A third plane was crashed into the Pentagon, the headquarters of the US military, at 9:37am, causing a partial collapse of one of the building’s sides. The fourth flight was flown in the direction of Washington DC – its target was likely either the White House or the US Capitol. However, the plane’s passengers were able to take back control from the hijackers and crashed the plane into a field in the US state of Pennsylvania. No one on the plane survived.

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A US flag posted in the rubble of the World Trade Centre in New York City on 13 September 2001. Photo: EPA-EFE

During the attacks, 2,977 people were killed – 265 people on the four planes, including the hijackers; 2,606 in the World Trade Centre and surrounding area, and 125 people at the Pentagon. More than 6,000 others were injured. Since then, many people have died of illnesses caused by exposure to dust from the site (called “Ground Zero”), including the more than 1,400 rescuers who helped people escape from the towers.

It remains one of the deadliest terror attacks in world history, and the first on American soil since Japan attacked the Navy base at Pearl Harbor, in the state of Hawaii, on December 7, 1941. This resulted in the US’ entry into World War Two.

The damaged area of the Pentagon building on September 16, 2001. Photo: Reuters

Who were the leaders during this time?

The mastermind behind the attacks was Osama bin Laden. He was the leader of al-Qaeda, a terrorist organisation he operated out of Afghanistan. He stated that the reasons for the attacks included the US’ support of Israel and pro-American governments in the Middle East. al-Qaeda also opposed Western influence in Muslim countries, and wanted to replace man-made laws with sharia law – a religious law based on a strict interpretation of Islam.

This undated photo shows al-Qaeda leader Osama bin Laden in Afghanistan. Photo: AP

The president of the US at the time was George W. Bush, who had only taken office earlier that year. Following the attacks, Bush announced a global War on Terror. It was thought at the time that bin Laden was hiding out in Afghanistan, but the government run by the Taliban – the same militant group that recently regained power – refused to give him up. Therefore, Bush announced that the US army would invade Afghanistan, overthrow the Taliban, and get Osama bin Laden themselves.

While the army did in fact drive out the Taliban, at least for a while, it would be another 10 years before Osama bin Laden was killed by US special forces in Pakistan, in an operation ordered by then-US President Barack Obama.

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US President George W. Bush shakes hands with Sergeant Major Vincent Camacho (L) prior to speaking to US troops during an unannounced visit to Bagram Air Base in Afghanistan on December 15, 2008. Photo: AFP

I’m confused - what does this have to do with Iraq?

In early 2002, during his annual State of the Union address, when the president gave updates to the American public about how the country was doing and what they planned for the next year, Bush said that an “axis of evil” consisting of North Korea, Iran and Iraq was “arming to threaten the peace of the world” and “posed a grave and growing danger,” and that his administration had the right to wage a preventive war. His government also repeated claims that the leader of Iraq, a dictator named Saddam Hussein, had weapons of mass destruction, and some officials accused Saddam of harbouring and supporting members of al-Qaeda.

In October 2002, Congress gave Bush the power to decide whether to launch a military attack in Iraq (previously, Congress had to approve of any decision first). The US invaded Iraq in March 2003, joined by its allies the UK, Australia and Poland. Saddam was captured in December that same year, and executed three years later.

This photo taken on November 28, 2006 shows ousted Iraqi President Saddam Hussein sitting in court as his trial resumed in Baghdad. On December 30, 2006, Saddam was hanged at the military intelligence headquarters in northern Baghdad after being found guilty of crimes against humanity. Photo: AFP

No weapons of mass destruction were ever found in Iraq, and a report from the National Commission on Terrorist Attacks Upon the United States, also known as the 9/11 Commission, found no evidence of a relationship between al-Qaeda and Saddam’s regime.

The supposed reasons for invading Iraq have faced heavy criticism, and many have called the move illegal under international law. The US invasion caused at least 100,000 civilian deaths, and the subsequent conflicts fought between the new Iraqi government and members of the Islamic State (ISIS) resulted in at least another 155,000 deaths and displaced five million people from their homes.

A photo from March 21, 2003, shows smoke covering the presidential palace compound in Baghdad, Iraq during a massive US-led air raid on the capital. Photo: AFP

What effect does all this have on life now?

It’s impossible to convey just how much the terrorist attacks on September 11, 2001, and the subsequent wars that followed, have changed the world over the last 20 years. Thousands of innocent people have lost their lives due to the fighting that followed, not to mention that the wars also sparked numerous humanitarian crises.

A girl places a flower on the edge of the North pool during ceremonies at the 911 Memorial on the 19th anniversary of the September 11, 2001 attacks in 2020. Photo: Reuters

Muslim Americans became targets for hate crimes and discrimination, and we can still see the devastating effects of anti-Muslim attitudes to this day (the mass shootings in two mosques in Christchurch, New Zealand that killed 51 people only happened in 2019). And a new brand of US nationalism arose within the country, cumulating in the Trumpism you see today, while conspiracy theories about the attacks could be considered the launch pad for many QAnon beliefs.

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