Twenty years after hijacked passenger jets crashed into New York City’s World Trade Center and the Pentagon outside Washington, DC, people in the United States have come together to honour the nearly 3,000 lives lost on September 11, 2001.

Saturday’s ceremony at the September 11 Memorial in New York City began with a moment of silence at 8:46am (12:46 GMT), the exact time the first of two planes flew into the World Trade Center’s twin towers.

Relatives then began to read aloud the names of 2,977 victims, an annual ritual that lasts four hours.

“We love you and we miss you,” many of them said as somber violin music played at the official ceremony, attended by dignitaries including President Joe Biden and former Presidents Barack Obama and Bill Clinton.

Mourners clutched photos of their loved ones, while music icon Bruce Springsteen sang his song I’ll See You in My Dreams. After nightfall, twin light beams will be projected into the New York sky.

“As we carry these 20 years forward, I find continuing appreciation for all of those who rose to be more than ordinary people,” said Mike Low, whose daughter was a flight attendant on the first plane.

The remembrances have become an annual tradition, but Saturday takes on special significance, coming 20 years after the morning that many view as a turning point in US history.

In a painful reminder of those changes, only weeks ago US and allied forces completed a chaotic withdrawal from the war the US started in Afghanistan shortly after the attacks in retaliation – which became the longest war in US history.

US forces toppled the Taliban, which had ruled Afghanistan since 1996, because the group had provided sanctuary to Osama bin Laden, leader of al-Qaeda, which carried out the 9/11 attacks. Bin Laden was hunted down and killed in Pakistan a decade later.

The Taliban, however, is now back in power in Afghanistan, while in Guantanamo Bay accused 9/11 mastermind Khalid Sheikh Mohammed and four other men continue to await trial, nine years after charges were filed.

At Ground Zero, 2,753 people, from all over the world, were killed in the initial explosions, jumped to their deaths, or simply vanished in the inferno of the collapsing towers.

At the Pentagon, an airliner tore a fiery hole in the side of the superpower’s military nerve centre, killing 184 people in the plane and on the ground.

And in Shanksville, Pennsylvania, the third wave of hijackers crashed into a field after passengers fought back, sending United 93 down before reaching its intended target – likely the US Capitol building in Washington.

The memorials come as national discord is overshadowing any sense of closure amid anger about the messy Kabul evacuation, which included 13 US soldiers killed by a suicide bomber, and stung by the broader realization of failure and defeat.

In a video posted on the eve of the anniversary, Biden urged Americans to show unity, “our greatest strength”.

“To me, that’s the central lesson of September 11th. It’s that at our most vulnerable, in the push and pull of all that makes us human, in the battle for the soul of America, unity is our greatest strength,” Biden said in a six-minute message from the White House.

Around the country
While many of the large events will happen in and around New York City, people across the country have planned events to remember those who died and to educate the public, including outside fire stations throughout New York in remembrance of the 343 firefighters who lost their lives.

At the Pentagon, headquarters of the US Department of Defense, a US flag will be unfurled on the west side where an aeroplane hit the building at precisely 9:37am EDT (13:37 GMT) on September 11, 2001.

Later, the department will hold a private ceremony to honour the 184 people killed there.

In Shanksville in southwestern Pennsylvania, family and guests will gather at the National Memorial there to honour the 40 people killed when United Airlines Flight 93 crashed in a farm field.

In Houston, people will gather on Saturday for the “9/11 Heroes Run”. At a US Navy training installation outside Chicago, 2,977 flags have been placed in a field to honour each of those killed in the attacks 20 years ago.