9/11: Twenty-five years, nearly 3,000 dead, a trial still unresolved

A quarter century after the era-defining attacks of September 11, the United States remains determined to keep alive the memory of a 2001 trauma that is fading as the proportion of Americans who did not experience it firsthand grows.

On that nearly cloudless day in 2001, al-Qaida operatives hijacked four planes with 19 hijackers aboard. Two jets slammed into the World Trade Center, causing the iconic 110-story buildings to collapse.

The attacks killed nearly 3,000 people across the four hijacked flights, the World Trade Center, and the Pentagon, making it the deadliest terrorist attack in U.S. history.

Hijackers flew a third plane into the Pentagon, while a fourth, apparently targeting the U.S. Capitol or the White House, crashed into a field near Shanksville, Pennsylvania, after passengers fought back.

Beyond those killed on Sept. 11, more than 9,400 other people have died from 9/11-related illnesses, according to the federal program established to provide medical care to those affected.

More than 400 firefighters, police officers, and paramedics lost their lives responding to the attacks on the World Trade Center. 

Recovery efforts at Ground Zero continued for nine months, officially ending in May 2002.

Authorities recently scheduled the trial of Khalid Sheikh Mohammed, alleged mastermind of the attacks and a top lieutenant of al-Qaida leader Osama bin Laden, for June 2028 at the U.S. Navy base in Guantanamo Bay, Cuba. He has been detained there for 20 years.

The attacks led the U.S. to launch its "war on terror," including the invasion of Afghanistan in October 2001 and later Iraq in 2003. The war in Afghanistan, the longest in U.S. history, ended with the withdrawal of American troops in August 2021.

"Many in my generation remember exactly where we were on that horrific day” in 2001, Beth Hillman, 59, president of the 9/11 Memorial & Museum and a U.S. Air Force veteran, told Agence France-Presse (AFP). Yet today, "100 million Americans were not even born or are too young to remember" the tragic events. 

The National September 11 Memorial opened to the public in 2011 on the attacks’ 10th anniversary.

"I wasn't born at the time, and yet it was important for me to be here, to do this trip," 22-year-old Ignacio Gaete, a Chilean, told AFP, visiting the museum and memorial featuring two large recessed pools within the footprints of the Twin Towers.