23 Years Later, These 9/11 Images Still Shock The World

Early in the morning, four planes were hijacked by terrorists. Two of these planes crashed into the Twin Towers of the World Trade Center in New York City. The towers, once symbols of America's strength, were destroyed in a matter of hours. A third plane hit the Pentagon, the headquarters of the US Department of Defense, in Arlington, Virginia. The fourth plane, United Flight 93, crashed into a field in Pennsylvania after passengers tried to overcome the hijackers.

The attacks caused immense destruction and loss of life. Nearly 3,000 people were killed, including passengers on the planes, workers in the buildings, and first responders who rushed to help. The aftermath of the attacks led to a global outpouring of sympathy and support for the United States.

Even after 23 years, images from that day still shock the world.

President Bush, in a reading seminar at the Emma E. Booker Elementary School in Sarasota, Florida, listens as White House Chief of Staff Andrew Card informs him of the second plane hitting the World Trade Center.

Pedestrians react in shock and horror as the World Trade Center towers collapse, with lower Manhattan covered in ash.

People look out from the burning North Tower of the World Trade Center as it is engulfed in flames.

A helicopter flies past the World Trade Center as a commercial plane crashes into it, illustrating the scale of the disaster.

The towers pour smoke shortly after being struck by hijacked aircraft, with the devastation visible from the surrounding area.

A rescue helicopter surveys the damage at the Pentagon, where firefighters battle flames following a hijacked plane crash.

The remaining tower, Tower 2, collapsed in a cloud of dust and debris about a half-hour after the first tower fell.

Firefighters walk through the rubble near the base of the destroyed South Tower of the World Trade Center in New York.

Rescue workers carry mortally injured New York City Fire Department chaplain, the Rev. Mychal Judge, from the wreckage of the World Trade Center. The chaplain was crushed by falling debris while giving last rites.

A man walks in the street near the World Trade Center towers.

One of the most haunting images from the attacks, ‘The Falling Man,’ captured by Richard Drew, shows a man falling from the North Tower against the backdrop of the collapsing building.