New York is marking 25 years since the September 11, 2001 terrorist attacks that killed nearly 3,000 people and changed America’s history.
The anniversary ceremony is taking place at the 9/11 Memorial in Lower Manhattan, where the World Trade Center’s Twin Towers once stood.
US President Donald Trump is not attending the New York ceremony. Instead, he is expected to pay his respects at the Pentagon, which was also targeted in the attacks.
Vice President JD Vance and four former presidents — George W. Bush, Barack Obama, Bill Clinton and Joe Biden — are expected at Ground Zero for the commemoration.
Bush was president when the attacks occurred, while Obama, Clinton and Biden are attending as former presidents.
The ceremony is also drawing attention because of the presence of New York Mayor Zohran Mamdani, the city’s first Muslim mayor.
Mamdani has faced calls to stay away from the commemoration, with a campaign led by the New York Post and former New York Mayor Rudy Giuliani.
A petition opposing his attendance has reportedly gathered more than 100,000 signatures, accusing Mamdani of associating with people who are allegedly dismissive of American institutions or insufficiently critical of extremist ideologies.
But supporters have criticised the campaign, arguing that Mamdani is being singled out because of his Muslim faith.
City Council member Shahana Hanif told CNN that it was concerning that the mayor was being treated differently simply because he is Muslim.
Mamdani has, however, received praise for recently releasing thousands of documents detailing what city officials knew about air toxicity in Lower Manhattan after the collapse of the World Trade Center.
The dust and pollution that followed the attacks exposed first responders, residents and workers to hazardous substances for months.
Thousands of people have since developed illnesses linked to their exposure.
Mamdani said earlier this week that people became sick because leaders they trusted told them it was safe to breathe the air when, according to the documents, officials had information indicating otherwise.
Investigators believe passengers on that flight attempted to regain control of the aircraft after learning about the other attacks.
A total of 2,977 people were killed in the attacks, excluding the 19 hijackers.
But the human cost has continued decades later.
More than 9,400 people have died from illnesses linked to the September 11 attacks, according to the federal programme established to provide healthcare and support to people affected by the disaster.
The anniversary is also becoming increasingly significant for younger Americans, many of whom were either not born or were too young to understand what happened in 2001.
For those who lost loved ones, however, the anniversary remains deeply personal.
Logan Miller, who lost an uncle in the attacks and later lost his grandfather to a 9/11-related illness, said younger generations often struggle to understand the scale of what happened.
He said their questions could also help keep the memory of the attacks alive.
Large crowds are expected at Ground Zero for the memorial ceremony, with authorities imposing extensive security measures around the site.
The US Secret Service has established a security perimeter around the 9/11 Memorial and Museum.
New York Police Commissioner Jessica Tisch said an anti-drone team would also be deployed as a precaution, although authorities said there was no specific intelligence indicating a threat to the event.
Ahead of Friday’s commemoration, New York Harbor was illuminated in a drone display featuring 2,977 lights, with each light representing one of the people killed in the September 11 attacks.
Twenty-five years later, the anniversary continues to serve as a moment of remembrance for families who lost loved ones, while also raising questions about the long-term health, political and social consequences of one of the defining tragedies of the 21st century.
