In pictures: The U.S. commemorates the 25th anniversary of 9/11

On September 11, 2001, members of Al-Qaeda hijacked four passenger airliners. They flew two planes into the twin skyscrapers of the World Trade Center in Manhattan around 9 a.m., causing both towers to collapse within hours. A third plane crashed into the Pentagon in Arlington, Va., while a fourth — likely intended for the U.S. Capitol building — crashed into a field in Shanksville, Pa. after an apparent struggle between passengers and hijackers.

The attack became the deadliest-ever terrorist attack on U.S. soil, killing nearly 3,000 people aboard the hijacked planes, in the towers and at the Pentagon. The attack was followed by the U.S. invasions of Afghanistan and Iraq amid a declared "War on Terror".

On the attack's 25th anniversary, Americans are remembering the victims with moments of silence and ceremonies at Ground Zero, the Pentagon and in Shanksville. All living former presidents, Vice President JD Vance and New York City Mayor Zohran Mamdani were among the notable officials present at the 9/11 Memorial and Museum, while President Trump spoke at the Pentagon ceremony. Below are a collection of photos showing how first responders and citizens are marking the occasion.