Attacks on buildings and structures in 2001

The September 11 attacks, colloquially known as 9/11, were a coordinated series of suicide attacks perpetrated by the Islamist terrorist organization al-Qaeda against the United States in 2001. Nineteen terrorists hijacked four airliners, then flew one into each of the Twin Towers at the World Trade Center in New York City. The third plane crashed into the Pentagon, the headquarters of the United States Department of Defense, in Arlington County, Virginia. The fourth plane crashed in a rural Pennsylvania field during a passenger revolt. In response to the attacks, the United States launched the global war on terror, seeking to eliminate hostile groups deemed terrorist organizations, and the governments purported to support them. This foreign policy agenda was conducted over the next two decades.

United Airlines Flight 93 was a domestic scheduled passenger flight that was hijacked by four Al-Qaeda terrorists on the morning of Tuesday, September 11, 2001, as part of the September 11 attacks. The hijackers planned to crash the plane into a federal government building in the national capital of Washington, D.C. The mission failed when the passengers fought back, forcing the terrorists to crash the plane in Shanksville in Somerset County, Pennsylvania, preventing them from reaching Al-Qaeda's intended target, but killing everyone aboard the flight. The airliner involved, a Boeing 757-200 with 44 passengers and crew, was flying United Airlines' daily scheduled morning flight from Newark International Airport in New Jersey to San Francisco International Airport in California, making it the only plane hijacked that day not to be a Los Angeles–bound flight.

event on 1 June 2001 in Kathmandu, Nepal in which Crown Prince Dipendra killed most of the royal family (including King Birendra and himself) with a gun

2001 terrorist attack on Indian parliament

Japanese disaster that killed 44 people in 2001

2001 religious violence between Christians and Muslims in Jos, Nigeria