25 years on, the 9/11 attacks reshaped security, politics and urban skylines

On 11 September 2001 four hijacked airliners were turned into weapons, killing 2,977 people from more than 100 nations and reshaping global security, foreign policy and the way cities think about tall buildings.

The attacks unfold

At 8.46 am American Airlines Flight 11, a Boeing 767‑200ER carrying 92 passengers, slammed into the North Tower of the World Trade Center in Lower Manhattan. The impact struck between floors 93 and 97, killing everyone on board and hundreds of office workers, including the entire staff of Marsh McLennan on those floors.

Seventeen minutes later, at 9.03 am, United Airlines Flight 175 crashed into the South Tower. The plane hit between floors 77 and 85 at roughly 587 mph, turning the aircraft into a missile that ignited a firestorm.

I don’t think the pilot is flying the plane. I think we are going down. I think they intend to go to Chicago or someplace and fly into a building. Don’t worry, Dad. If it happens, it’ll be very fast… Oh, my God… oh, my God, oh, my God.

The desperate words were spoken by passenger Peter Hanson on an Airfone just minutes before the impact.

At 9.10 am, while reading to a second‑grade class in Florida, George W. Bush was quietly informed that a second plane had struck the second tower. His chief of staff, Andrew Card, whispered the news, and the President’s measured silence was captured by cameras worldwide.

Immediate response and further devastation

At 9.37 am a third aircraft, an American Airlines Boeing 757, hit the west side of the Pentagon in Virginia, killing all 64 passengers and crew and adding 125 more deaths among building occupants. Donald Rumsfeld, then secretary of defence, rushed to the scene to assist the injured.

The fourth hijacked plane, United Airlines Flight 93, was headed for Washington, D.C. Passengers, aware of the earlier crashes, fought the hijackers. Their struggle ended at 10.03 am when the aircraft crashed in a field near Stonycreek, Pennsylvania, killing everyone on board but averting a likely strike on the U.S. Capitol.

The South Tower collapsed at 9.59 am, followed by the North Tower at 10.28 am. The twin towers, once symbols of economic power, were reduced to rubble, and the death toll eventually reached 2,977.

Legacy and what lies ahead

U.S. intelligence quickly identified the perpetrators as Al‑Qaeda, led by Osama bin Laden. The attacks prompted the launch of the “Global War on Terror”, a campaign that has defined U.S. foreign policy for two decades and led to prolonged conflicts in Afghanistan and Iraq.

Domestically, the events spurred sweeping reforms: the creation of the Department of Homeland Security, the introduction of the USA PATRIOT Act, and a permanent overhaul of airport screening procedures. The psychological impact on the American public and the world’s perception of security risk remains profound.

Urban planners also took note. The loss of the towers forced a re‑evaluation of skyscraper safety, fire‑proofing standards and evacuation protocols, a topic still debated in cities such as London as new high‑rise projects rise.

As the anniversary passes, policymakers continue to grapple with the balance between security and civil liberties, while families of victims seek accountability and remembrance. The phrase spoken by George Tenet, then director of central intelligence, that “the world changed 25 years ago”, still resonates in debates over surveillance, counter‑terrorism funding and the future of international cooperation.

In the years since, the physical scars have been rebuilt, the new World Trade Center complex is nearing completion, but the strategic and cultural reverberations of that September Tuesday endure, shaping how nations confront threats in an increasingly complex world.