The world is marking 25 years since the September 11 attacks in the United States, which claimed the lives of nearly 3,000 people.

Memorial services are being held in New York City, at the Pentagon in Virginia and in Shanksville, Pennsylvania, where families, survivors and first responders are gathering to remember those who died.

In New York, victims’ names are being read at the 9/11 Memorial, with moments of silence marking the attacks. A new moment of silence this year will honour first responders and survivors who later died from illnesses linked to 9/11.

Audio of Flight 175 impact resurfaces

As the anniversary is being marked, a clear audio recording capturing the approach and impact of United Airlines Flight 175 has resurfaced.

The Boeing 767, carrying 65 people, struck the South Tower of the World Trade Centre at 9:03 am local time, just 17 minutes after the North Tower had been hit.

The recording captures the aircraft approaching before the impact. It has prompted strong reactions from social media users, with many saying the audio makes the events of that day feel particularly immediate and real, even 25 years later.

Please note: The audio is distressing and may upset some listeners:

This is perhaps the clearest audio of flight 175 barreling down and eventually into the south tower.

Those 2 young men, as well as millions of others who were rather in manhattan that day or watching events unfold live, knew in that instance that this was no longer an accident,… pic.twitter.com/kOrmXsu6ws

— TheOlChippy (@TheOlChippy) September 11, 2026

Tributes and remembrance events are taking place in communities across the US and around the world.

Twenty-five years on, many people still remember exactly where they were when the news broke. Where were you?

This may be one of the most shocking firsthand videos from September 11, capturing the South Tower collapsing as terrified people run for cover.

25 years later, the terror of that moment remains unimaginable. 😟 pic.twitter.com/CcwTZCM5rm

— Brandon Tatum (@TheOfficerTatum) September 9, 2026

Raw 9/11 footage by Park Foreman / taken from near State and Clinton Streets, Brooklyn. United Airlines Flight 175 was the second plane hijacked on September 11, 2001, and it crashed into the South Tower of the World Trade Center.

Many people weren’t even born yet, while others… pic.twitter.com/1ka6nHQAps

— Adi (@Adi13) September 6, 2026

2977 drones fly over NYC, one for each victim of 9/11, to recreate the twin towers! 🇺🇸 🇺🇸 pic.twitter.com/unSI77jX4x

— Rob Vendetti (@rob_vendetti) September 11, 2026

Today, I attended a memorial mass at St. Patrick’s Cathedral, led by Archbishop Ronald A. Hicks, in honor of those who died on 9/11.

25 years ago, we bore witness to unimaginable suffering. But New Yorkers met that moment with a spirit of love, sacrifice, and solidarity that…

— Mayor Zohran Kwame Mamdani (@NYCMayor) September 11, 2026

Today, we remember.

We remember that 25 years ago, the world stood still.

We remember the 3,000 people who left home that morning and never returned.

Where the Twin Towers once stood, two columns of light now rise into the New York sky.

They remind us that light triumphs… pic.twitter.com/YcYi52NgiU

— Ursula von der Leyen (@vonderleyen) September 11, 2026

Anyone who witnessed the terrible events of 9/11 unfold 25 years ago will never forget them.

Time has not faded our memory of the thousands of innocent people who were killed in the most appalling acts of terrorism – including 67 Britons, many of whom were from London.

Today…

— Mayor of London, Sadiq Khan (@MayorofLondon) September 11, 2026