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The attacks of 2001 were not the first to hit the World Trade Center.

On 26 February 1993, at 12:17 ET an explosion in the parking garage beneath the towers blew a 100ft (30m) crater through several floors.

Many people were injured in the evacuation and six people died that day. They are also remembered in the memorial pools at the site today.

Later, a search through the rubble revealed a vehicle identification number from a rental van reported stolen the day before. The vehicle had been rented by Mohammad Salamah, who was traced through a previous criminal record and arrested when he tried to get the deposit on the van back.

His arrest led to the detention of a further three suspects - Nidal Ayyad, Mahmoud Abouhalima, and Ahmed Aja. All four were tried, convicted and sentenced to life in prison.

Three more plotters were identified, with two more arrested in 1995 - Ramzi Yousef, who planned the attack, and Eyad Ismoil, the van driver. The seventh, Abdul Yasin, remains at large.

According to the FBI, external, the plan was to topple one tower into the other and served as something of dress rehearsal for 9/11. Yousef’s uncle is Khalid Sheikh Mohammed, who will stand trial for his role in the 2001 attacks in June 2028.

Americans have paid tribute to the lives lost on 9/11 at ceremonies across the country to mark 25 years since the attacks.

"We will never, ever forget, that's why we fight today," President Donald Trump said earlier today at a ceremony at the Pentagon.

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Governor Josh Shapiro of Pennsylvania says the heroism of those aboard the hijacked Flight 93 - which crashed into an empty field after passengers stormed the cockpit - "inspired a nation".

Speaking at the Flight 93 National Memorial in Stoystown, Pennsylvania, he says the site serves as a "powerful and painful" reminder of a "dark chapter" in the American story.

He describes the passengers as "heroes", adding that they were "ordinary Americans who did an extraordinary thing".

"They did not wake up that morning with the expectation that they would find themselves on the frontline of a war," Shapiro says. "They did not let that fear control them."

He says their actions that day saved "countless lives".

The memorial service is under way at the memorial to the victims of Flight 93 in Shanskville, Pennsylvania.

On 9/11, a United Airlines plane crashed into an open field after passengers attempted to fight back against the hijackers. All 40 passengers and crew died.

Every year dignitaries, families, and mourners make the journey to the rural county where the memorial is located to pay their respects.

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Perhaps one of the most striking traditions in which New York remembers those lost during the September 2001 attacks is the Tribute in Light.

This public art installation returns every year, shining twin beams of light up to four miles into the sky - visible from up to 60 miles (95km) from downtown Manhattan.

The beams consist of 88 7,000-watt xenon lightbulbs positioned in two 48ft (14m) squares, approximately in the same shape and positioning of the Twin Towers.

Bernd Debusmann Jr
White House reporter

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In the last hour of so, the CIA has released 71 Presidential Daily Briefs which show the intelligence community's increasing alarm over the threat posed by al-Qaeda ahead of 9/11.

These briefings, which are given to the president at the White House, are considered among the most secretive in the US intelligence community and provide broad intelligence community findings that the officials believe are important enough to warrant the president's attention.

Those released today stem from both the Clinton and Bush administrations. The documents were created between 1998 and 12 September 2001. Bin Laden was already well-known to US intelligence officials following attacks on US embassies in Kenya and Tanzania that year.

While the earlier documents broadly assess Bin Laden as a threat with the intention of attacking the US or American targets abroad, they grow in urgency over time.

One document from August 2001 - which has been previously reported - explicitly notes that Bin Laden was "determined" to attack the US and was likely preparing to do so.

The final, heavily redacted, document, was issued by the CIA the day after the attacks. The top portion notes that the attack was likely "widely known" in extremist circles and that Bin Laden reportedly relocated to Kabul ahead of the attacks.

It also notes that Mullah Omar, the then-head of the Taliban, was evacuated from his residence shortly after the attack.

Image source, Courtesy of the George W. Bush Presidential Library/Getty Images

US President George W Bush - who we saw earlier attending a 9/11 ceremony in New York - was in Emma E. Booker Elementary School in Sarasota, Florida reading The Pet Goat with a group of seven year olds when he was informed about the 9/11 attacks.

Video of the day shows the exact moment the president's chief of staff relayed the message that a plane had struck the South Tower, bringing into realisation that the first plane that hit the North Tower wasn't an accident.

“A second plane hit the second tower. America is under attack,”Andrew Card whispered into the president's ear.

News cameras captured Bush's facial expression, his demeanour shifting from cheerful to still as he tried to compose himself in front of the young children.

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"During a crisis, it's really important to set a tone and not to panic and so I waited for the appropriate moment to leave the classroom," Bush said years later in a BBC documentary.

Later, Bush addressed the nation from the school's gym. "Today we've had a national tragedy... Terrorism against our nation will not stand," he said.

Minutes later, a third plane was flown into the Pentagon headquarters, a short distance from the White House.

You can watch Bush's reflection of the moment here.

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Reconstruction at the site of the largest terrorist attack in US history was a delicate balancing act of commemorating those lost, while rebuilding critical infrastructure and commercial confidence in the financial capital of the world.

In addition to the memorial sites and tributes we’ve documented today, the World Trade Center - known for years as Ground Zero - itself has been reborn.

Standing tallest at 1,776ft (541m) is One World Trade, home to technology, finance, and investment firms, as well as the headquarters for publishing giant Condé Nast.

Across the street, Seven World Trade, the first new tower to be rebuilt, is home to Moët Hennessy and Moody’s, and adjacent is the Perelman Performing Arts Center (technically Six World Trade).

Three World Trade sits beside the transit hub and shopping centre, the Oculus, while its neighbour Four World Trade is home to Spotify and the Port Authority. They are currently the second and third tallest of the buildings on site.

Both will be overtaken by Two World Trade, construction of which has just begun. When completed, it will be the global headquarters of American Express.

Five World Trade has not yet begun construction and is currently paused, but it is planned as a residential development, including affordable housing.

A memorial ceremony is about to begin near Shanksville, Pennsylvania, where on 11 September 2001, the hijacked Flight 93 crashed in an empty field after passengers stormed the cockpit.

We're expecting to hear from US Secretary of Transportation Sean Duffy.

You can read along here or click watch live above.

Image source, Reuters

Former Vice-President Mike Pence, former New York City Mayor Michael Bloomberg, and former UK Prime Minister Tony Blair have all recently shared remarks honouring the victims of 9/11.

"On this solemn anniversary of September 11th, let us remember the 2,977 innocent souls who perished at the hands of our terrorist enemies," Pence said. "And let us also honor those who gave their lives in the long struggle that followed."

Bloomberg, who is also the chairman of the National September 11 Museum and Memorial, said the sky was crystal clear and bright blue on 9/11.

"I had just cast my ballot when I heard that a plane had hit the World Trade Center," he said. "In the face of unimaginable tragedy and loss, New Yorkers and people across the country responded with bravery, resilience and hope."

Blair, who was the UK prime minister at the time, said in a video statement that "that day changed the world".

"The struggle against terrorism in all its form continues," he added.

The seventh moment of silence has just been observed - a new and permanent addition to the ceremonies this year.

Sounding the bell for the seventh time and the following silence commemorate those who died of health complications following the 11 September attacks.

US officials say disease has now claimed three times the number of lives that the actual attacks did.

The seventh bell also marks the end of the reading of the names of the victims.

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The only house of worship destroyed during the 2001 attacks, the original St Nicholas Greek Orthodox Church, was founded in 1916 a small house in lower Manhattan that was formerly a tavern. It remained in operation at the same location at 155 Cedar Street.

Thankfully, no one was at the church when it was completely demolished by the collapse of the South Tower of the World Trade Center.

After negotiations with Port Authority - the entity in charge of the World Trade Center complex - to rebuild, it was settled that it would be part of the wider redevelopment of the site and would sit at the end of Liberty Park overlooking the memorial plaza.

Architect Santiago Calatrava was chosen to lead the project, which drew artistic inspiration from the Hagia Sophia in Istanbul. The design sees the church glow at night as a "spiritual beacon of hope and rebirth".

Its doors are open to all to light a candle in remembrance.

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Former President Joe Biden, who is present today at the memorial in New York City, shared some words on social media honouring the victims and first responders killed on 11 September.

"This morning, Jill and I hold close the families who carry that loss every day. We honor the heroes of September 11th: the firefighters and police officers who rushed into the towers and the Pentagon, the passengers who fought back over Shanksville, and the generation that stepped up to serve in the aftermath," he wrote.

Hillary Clinton, the former US secretary of state, said "the consequences have continued for 25 years", and it's our job to inform younger generations who are too young to remember the attacks.

"Something worth remembering 25 years after 9/11: in the aftermath of catastrophe, people look around, they see what is needed, and they help," she wrote online.

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Former New York City Mayor Eric Adams has also spoken out.

"Cowardly terrorists stole all of that in an act of pure evil. They murdered innocent people and left families with a pain that no anniversary can erase," he said. "As a New Yorker and a former NYPD officer, this will always be personal to me."

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Surrounding the memorial pools and the 9/11 Museum are approximately 400 swamp white oak trees, a species native to all three crash sites from the 2001 attacks in New York, Arlington, Virginia, and Shanksville, Pennsylvania.

They form a calm space in the heart of downtown Manhattan and provide welcome shade during New York's fierce summer heat.

There is also one tree different from the others - a Callery pear tree - that was discovered severely damaged underneath the rubble in October 2001. New York City's Parks and Recreation Department removed it from the site and nursed it back to health.

The tree was then replanted at the site of the World Trade Center as a symbol of resilience and perseverance.

Nearby, an open space among the trees - known as the Memorial Glade - is dedicated in honour of those who are sick or have died from exposure to toxins in the aftermath of the attacks, including first responders, survivors and volunteers. They will be remembered today with a new seventh sounding of a bell and a moment of silence.

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Marcy Borders became the subject of one of the most enduring images of the 9/11 attacks.

She was just one month into a job at a Bank of America office on the 81st floor of the North Tower when a plane hit it.

"The building started quaking and swaying. I lost all control, and I went into a frenzy. I fought my way out of that place," Borders later recounted.

Defying instructions from her boss to stay put, she fled down the stairway and into the lobby of an adjacent building where she was photographed by Stan Honda, a photojournalist at the AFP news agency.

Covered in dust, her shell shocked face was emblematic of the nation's mood. In the media, Borders became known as the "Dust Lady".

Following the attacks, Borders suffered from severe depression and addiction. She died in August 2015 from stomach cancer, one of the most common cancers diagnosed in 9/11 survivors.

"Not only is she the 'Dust Lady' but she is my hero and she will forever live through me," her daughter Noelle Borders said following her death.

As you will have seen from our coverage today, every year on 11 September, bells ring to commemorate the exact time that each of the four planes crashed, and the exact time that the Twin Towers fell.

Each of the six bells is followed by a moment of silence.

This year, a seventh bell will ring. Its purpose is to commemorate the thousands who died from diseases including cancer after the attacks.

Illnesses related to dust and smoke from the towers' collapse have since claimed more than threefold the nearly 3,000 lives lost in the attacks, US health officials say.

“As the years pass and the human toll grows, we reckon with the cost of September 11th whenever another New Yorker is stolen from us too soon,” New York City Mayor Zohran Mamdani has said. “Now, close to 25 years later, more people have died from 9/11-related illnesses than were killed on the day itself.”

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The 9/11 Memorial covers eight acres of the 16 acre World Trade Center campus in New York. Dominating the space are the two large memorial pools set within a plaza of approximately 400 swamp white oak trees.

The design, Reflecting Absence, was submitted as part of an international competition by architect Michael Arad and landscape architect Peter Walker.

Featuring twin waterfall pools surrounded by bronze parapets listing the names of the victims of the 2001 attacks and the earlier 1993 bombing of the World Trade Center, they mark out the footprints of the two towers.

Covering about an acre each, they contain the largest human-made waterfalls in North America, each descending 30ft (9m) into a square basin where water continues to fall another 20ft into a smaller central void.

The memorial opened on 11 September 2011, ten years after the attacks

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Commerce Secretary Howard Lutnick, who is at the New York memorial today, is honouring his brother, Gary, who was killed alongside many of their colleagues at Cantor Fitzgerald's offices at the top of the North Tower of the World Trade Center.

Lutnick says his brother Gary was "the kindest and most fun person I knew".

"Gary was happy in every photo. Over the past 25 years, nearly every day there has been a moment when I’ve thought to myself, I wish Gary was here," Lutnick says.

"Gary was killed at the young age of 36 for being an American and going to work that morning in the greatest country in the world. I love and miss you every day, my brother," he adds.

Cantor Fitzgerald accounts for the largest loss of life of a single organization during the attacks, with 658 employees losing their lives.

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We're continuing to show you some of the other ways the city commemorates the victims of 9/11 and how these memorials have reshaped the city's architecture:

In Liberty Park, in an elevated garden overlooking the 9/11 Memorial, stands the heavily dented black and gold Koenig Sphere, which once sat at the heart of the original World Trade Center development.

The 25ft (7.5m) tall cast bronze sculpture weighs 25 tonnes and was originally commissioned in 1966 as a centrepiece for the plaza between the towers.

The work of German artist Fritz Koenig, it was dedicated to “world peace through trade” and was the largest bronze sculpture of modern times.

The sphere was the only work of art recovered from the rubble after the 9/11 attacks. It was dismantled and stored before being relocated to Battery Park in 2002, then moved to its current position in 2017.

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Memorials are continuing to be held across New York City today as the city commemorates those who died on 9/11.

Here's a look back at what we've seen in the last 24 hours:

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