11 September 2001

11 September 2001
Flickr user Michael Foran · CC BY 2.0 · source
Title	11 September 2001
Date	11 September 2001
Location	New York City, Arlington County, Virginia, Pennsylvania
Target	World Trade Center, The Pentagon (United States), United States Capitol
Fatalities	2,977 (approximate)
Perpetrators	al-Qaeda
Weapons	Hijacked airliners

11 September 2001 was a series of coordinated terrorist attacks carried out on 11 September 2001, in which four commercial airliners were hijacked and used as weapons against high-profile targets in the United States. The attacks struck the World Trade Center in New York City, The Pentagon (United States) in Arlington County, Virginia, and, after passenger resistance, crashed near Shanksville, Pennsylvania en route to an intended target such as the United States Capitol or The White House. The events precipitated major shifts in United States foreign policy, United States domestic policy, international security law, and global counterterrorism operations.

Background and Planning

Planning for the operation was attributed to senior leaders of al-Qaeda, including Osama bin Laden and Khalid Sheikh Mohammed. The plot drew on operational methods previously used in attacks like the 1993 bombing of the World Trade Center and the 2000 attack on the USS Cole; planners drew inspiration from ideologues such as Sayyid Qutb and organizational models developed in Afghanistan during the Soviet–Afghan War. Logistics involved operatives trained in aviation in the United States, with assistance from cells connected to networks in Pakistan, Saudi Arabia, United Arab Emirates, and Germany. Financing and facilitation allegedly involved interactions with entities previously implicated in investigations of 1998 United States embassy bombings and shadow facilitators linked to charities scrutinized after the 1993 World Trade Center bombing.

The Attacks

Four flights were commandeered shortly after takeoff: American Airlines Flight 11, United Airlines Flight 175, American Airlines Flight 77, and United Airlines Flight 93. Hijackers using box cutters incapacitated crew and passengers, redirecting aircraft toward symbolic targets. Flight 11 struck the North Tower of the World Trade Center and Flight 175 struck the South Tower; both impacts ignited fires that led to progressive structural failure and collapse. Flight 77 crashed into The Pentagon (United States), breaching the Defense Department complex. Flight 93, after resistance by passengers including Todd Beamer, Mark Bingham, Tom Burnett, and Jeremy Glick, crashed near Shanksville, Pennsylvania, preventing an attack on either the United States Capitol or The White House.

Immediate Aftermath and Rescue Efforts

First responders included units from the New York City Fire Department, New York City Police Department, Port Authority of New York and New Jersey Police Department, Arlington County Fire Department, and United States Secret Service. Evacuations from skyscrapers such as One World Trade Center and WTC 7 were coordinated with assistance from agencies like Federal Aviation Administration and Mass Transit Authority (New York). Emergency medical response involved hospitals such as NewYork–Presbyterian Hospital, Bellevue Hospital Center, and George Washington University Hospital. Search-and-rescue drew volunteers from organizations including American Red Cross, Salvation Army, and numerous volunteer firefighter and police organizations across New Jersey and Connecticut.

Casualties and Damage

Approximately 2,977 victims died, including civilians, first responders, and passengers; among the dead were employees of corporations headquartered in the towers such as Cantor Fitzgerald and Marsh & McLennan Companies. Structural failures resulted in complete collapse of the Twin Towers and extensive damage to ancillary buildings in the World Trade Center (1973–2001) complex, including WTC 7. The Pentagon sustained severe structural and personnel losses. Economic impacts affected institutions such as the New York Stock Exchange, NASDAQ, and insurance firms; air travel was grounded by the Federal Aviation Administration for several days, affecting carriers including American Airlines and United Airlines.

Investigations and Accountability

Post-attack inquiries included the 9/11 Commission (officially the National Commission on Terrorist Attacks Upon the United States), the FBI’s investigations, and congressional hearings. The 9/11 Commission report examined failures of intelligence sharing involving agencies such as the Central Intelligence Agency, National Security Agency, and Federal Bureau of Investigation. Legal and military responses involved designations of al-Qaeda operatives on lists maintained by the United Nations Security Council and sanctions administered by bodies like the United States Department of the Treasury. Some perpetrators were targeted in counterterrorism operations such as the United States invasion of Afghanistan (2001) and intelligence-driven actions culminating in later operations against Osama bin Laden.

Domestic and International Responses

Domestically, the United States Congress passed the USA PATRIOT Act and established the Department of Homeland Security, reorganizing agencies including Transportation Security Administration and Immigration and Naturalization Service functions. Internationally, NATO invoked Article 5 of the North Atlantic Treaty for the first time, prompting coalition support for operations in Afghanistan under the Operation Enduring Freedom banner. Global reactions ranged from solidarity demonstrations in cities like London, Paris, Berlin, and Tokyo to security overhauls at airports such as Heathrow Airport and Charles de Gaulle Airport.

Long-term Consequences and Legacy

Long-term effects included prolonged military engagements such as the War in Afghanistan (2001–2021) and policy debates over practices like rendition, detention at Guantanamo Bay Naval Base, and coercive interrogation techniques scrutinized in reports like the Senate Intelligence Committee report on CIA interrogation. Domestic surveillance expansions involved programs by NSA and legal challenges in courts such as the Supreme Court of the United States. Memorialization efforts produced sites and institutions including the National September 11 Memorial & Museum, rebuilding projects such as One World Trade Center, and cultural responses in literature, film, and art referencing figures like Don DeLillo and institutions like Museum of Modern Art (New York). The attacks reshaped international counterterrorism law, diplomacy among states like Pakistan, Saudi Arabia, and Iraq (pre-2003) and influenced global security norms into the 21st century.

Category:Terrorist incidents in the United States