A quarter of a century after the deadliest attack on ⁠US soil, Americans gathered on Friday to commemorate the nearly 3,000 lives lost on September 11, 2001.The Al Qaeda attack was arguably the most defining event of this century so far, and has shaped countless lives across the globe, particularly in the Middle East during a string of US-led wars. Former presidents George W Bush, Bill Clinton, Barack Obama and Joe Biden joined New York Mayor Zohran Mamdani and Vice President JD Vance at the National September 11 Memorial in Manhattan. The ceremony began at 8:46 am with a moment of silence, marking the time American Airlines Flight 11 hit the World Trade Centre’s North Tower. Family members then began reading the names of all 2,977 people who were killed, as well as the six people killed in the 1993 World Trade Centre bombing.Thousands more have died in the years since 9/11, many from inhaling toxic dust from the collapsed buildings and debris in New York. Alexander Romero, who was two years old when his father Elvin Romero was killed in the Twin Towers, paid tribute to his dad. "Don't leave anything left unsaid, and try to make the absolute most of the limited time that we all have here," he said. "I love you. I wish I got to know you. Please keep looking out for all of us and keep us safe. We miss and we love you".The attacks shaped generations of Americans who lived through the day or grew up in its aftermath, influencing US foreign policy, domestic politics and public attitudes ⁠toward security.President Donald Trump commemorated the occasion at the Defence Department. "We will never, ever forget. That's why we fight today," he said in a speech outside the Pentagon, in the location American Airlines Flight 77 struck the military headquarters.Mourners also held a ceremony in Shanksville, Pennsylvania, at the crash site where passengers brought down a fourth hijacked jetliner that had been headed for Washington.'War on terror' The attacks initiated America's "war on terror," which led to the creation of the Department of Homeland ​Security and the US invasions of Afghanistan and Iraq that lasted years. The resulting public backlash helped fuel Mr Trump's rise a decade ‌ago, when he vowed not to start new foreign entanglements — a ⁠promise being tested by the current Iran war.According to Brown University's Watson School of International and Public Affairs, which has spent years tracking the costs of the post-9/11 wars, the US has spent or is obliged to spend about $8 trillion on military intervention and associated costs. That figure does not include interest payments on borrowing to fund the wars.Brown says it has also tallied that at least 940,000 people have died due to direct war violence, including civilians, armed forces on all sides, contractors, journalists and humanitarian workers.At home, Americans expressed deep solidarity and ​patriotism, as well as sorrow, in the immediate wake of the attacks.At the same time, however, Muslim Americans and immigrants from Muslim-majority countries faced a ​rise in prejudice and hate crimes. ‌Community members gather at a vigil for victims and families of a shooting at the Islamic Centre of San Diego, California, on May 19, 2026. AFPShow caption: Community members gather at a vigil for victims and families…Public polls have found 9/11 continues to shape Americans' perceptions of Muslims to this day. Mr Mamdani, New York's first Muslim mayor, has faced calls from some Republicans to skip Friday's ceremony, which he has rejected.