However as we approach the 20th anniversary of the September 11 attacks, we should also remember the tragedies that took place following the hijacking of two more planes - a third which flew into the west side of The Pentagon building, and a fourth, United Airlines Flight 93, which landed in a field in Pennsylvania.
Passengers and crew on that flight were praised for their heroic efforts to regain control of the plane - however all 44 people on board were killed, including the four hijackers.
So what happened on board United Airlines Flight 93, what was its original target, where did it land - and who were the passengers and crew praised for their bravery on that fateful day?
What happened on board United Airlines Flight 93?
United Airlines Flight 93 was a domestic scheduled passenger flight flying from Newark International Airport in New Jersey to San Francisco International Airport in California when it was hijacked by four al-Qaeda terrorists.
The hijackers stormed the aircraft’s cockpit just 46 minutes after takeoff on September 11 2001, and a struggle - transmitted to Air Traffic Control - ensued between the captain, Jason Dahl and first officer LeRoy Homer Jr.
Ziad Jarrah, a member of Al-Qaeda who had trained as a pilot, took control of the aircraft. He told passengers: “Keep remaining sitting. We have a bomb on board.”
The passengers were moved to the back of the plane and Jarrah diverted it back towards the east coast, in the direction of Washington DC.
Many of the passengers and crew had already heard through phone calls about the attacks on the World Trade Center and The Pentagon. But rather than giving up, many of them tried to take back control of the plane.
After the plane’s voice data recorder was recovered, it revealed pounding and crashing sounds against the cockpit door and shouts and screams.
One passenger cried “Let’s get them!” and a hijacker shouted “Allahu akbar”. Jarrah tried to knock passengers off their feet by rocking the plane but the passengers continued their efforts.
A male passenger is heard in the recording saying, "Turn it up!" and a hijacker says, "Pull it down! Pull it down!"
Jarrah is then heard pleading: “Hey! Hey! Give it to me. Give it to me. Give it to me. Give it to me. Give it to me. Give it to me. Give it to me. Give it to me.”
The plane crashed upside down into a field in Pennsylvania, killing everyone on board.
Who was Todd Beamer?
Todd Beamer was one of the passengers on board United Airlines Flight 93. After the hijackers on the plane herded the passengers to the back, Beamer tried to make a call through a phone located on the back of a plane seat.
However, it went to a customer-service representative who passed him on to GTE airphone supervisor Lisa Jefferson.
As FBI agents listened on the call, Beamer explained how hijackers had taken over the plane, and that one passenger had been killed.
He said the terrorists had knives and one appeared to have a bomb strapped around his waist. When the plane veered sharply downwards, he exclaimed “We’re going down! We’re going down!”
According to accounts of mobile phone conversations, Beamer hatched a plan with fellow passengers Mark Bingham, Tom Burnett, and Jeremy Glick to take back the plane.
Other passengers including Lou Nacke, Rich Guadagno, Alan Beaven, Honor Elizabeth Wainio, Linda Gronlund, and William Cashman, along with flight attendants Sandra Bradshaw and CeeCee Lyles got involved in the discussion and voted on a course of action.
They decided to storm the cockpit and take over the plane, and Beamer communicated this to Jefferson on the phone.
He said they were planning to “jump on” the hijackers and fly the plane to the ground before the terrorists could follow through with their plan.
Beamer recited the Lord’s Prayer and the 23rd Psalm with Jefferson, and others joined in.
He then said to Jefferson, “If I don’t make it, please call my family and let them know how much I love them.”
Beamer’s last words heard by Jefferson were: “Are you ready? Okay. Let’s roll.”
When the plane crashed, Beamer died alongside everyone else on board.
Weeks after the attacks, President George Bush praised the courage of United 93’s passengers in an address to a joint session of Congress and the American people, naming Beamer in particular, who he called “an exceptional man.”
Then in November 2001, Bush cited Beamer’s last words in an address from the World Congress Center in Atlanta.
He said: "Some of our greatest moments have been acts of courage for which no one could have been prepared. But we have our marching orders. My fellow Americans, let’s roll!"
Was the plane shot down?
Former Vice President Dick Cheney authorised Flight 93 to be shot down before it crashed. On hearing of the crash, he reportedly said, “I think an act of heroism just took place on that plane.”
According to former president George W. Bush’s memoirs, he initially believed that Flight 93 had been shot down on his orders but it later emerged that passengers had stormed the cockpit.
Where did the plane crash?
At 10.03.11 on September 11 2001, Flight 93 crashed into a field near Indian Lake and Shanksville, Pennsylvania.
The flight hit the ground upside-down at a 40-degree nose-down angle. It was flying at 563mph on impact, and left a crater eight to 10 feet deep and 30 to 50 feet wide.
According to the coroner, everyone on board who was still alive at the time of the crash, died instantly of blunt-force trauma.
Human remains were so fragmented from the impact that it took until December 21 to identify all the people on board, however it could not be ascertained whether any victims were dead before the plane crashed.
What was its target?
Flight 93’s intended target has never been conclusively confirmed, but it’s been speculated that it was either the White House or The Capitol building.
According to a report by the National Commission of Terrorist Attacks Upon the United States, senior Al-Qaeda members, Khalid Sheikh Mohammed, Osama bin Laden and Mohammed Atef had a list of potential targets.
While Bin Laden wanted to destroy the White House and Pentagon, Khalid Sheikh Mohammed wanted to hit the World Trade Centre. All three wanted to hit the Capitol.
While Bin Laden reportedly preferred the White House as a target, there were concerns this would be too difficult.
In the end, Mohamed Atta, the architect of the operation, informed Bin Laden that Jarrah would target the Capitol building.
A further exchange between Atta and key facilitator of the attacks, Ramzi bin al-Shibh two days before the attacks, it emerged that the White House would be the primary target and the Capitol the secondary target.
The pilots were instructed to crash the plane if they couldn’t reach their intended target.
How many people were killed?
Seven crew members and 33 passengers were killed in the crash, along with the four hijackers. A total of 44 people died.
Thirty passengers were from the US, and there was one passenger from Germany, one from Japan and one from New Zealand.
All seven crew members were from the United States.
Where is the memorial?
A memorial area with a white marble Wall of Names was dedicated on 10 September 2011, the day before the 10th anniversary of the crash.
The design for the memorial is a modified version of the entry Crescent of Embrace by Paul and Milena Murdoch.
A visitor centre made of concrete and glass then opened on 10 September 2015 and is located on a hill overlooking the memorial.
Both the visitor centre and Wall of Names are aligned with the flight path. The final piece, ‘the Tower of Voices; was dedicated during a ceremony on 9 September 2018.
The memorial is located in Stonycreek Township, Pennsylvania.
How do I watch United 93 in the UK?
United 93, a thriller film from British director Paul Greengrass (Captain Philips) documents the events that took place on board the flight, as well as the experience of air traffic control operators.
It was released in 2006 and opened to critical acclaim in the US.
The film is not available to watch on Netflix UK, but it is available on Amazon Prime Video.
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