United Airlines plane heads for the south tower of the World Trade Center
September 11 terrorist attacks, also called 9/11, were the worst acts of terrorism ever carried out against the United States. On Tuesday, Sept. 11, 2001, terrorists hijacked four commercial jetliners and crashed two of them into the twin towers of the World Trade Center in New York City, and one into the Pentagon Building near Washington, D.C. Hijackers crashed the fourth jet in a Pennsylvania field to prevent it from being reclaimed by passengers. The attacks killed about 3,000 people, including the 19 hijackers.
The U.S. government linked the attacks to al-Qa`ida (also spelled al-Qaeda), an Islamic extremist group founded by the Saudi-born millionaire Osama bin Laden. Bin Laden had previously issued a fatwa (religious edict) calling for Muslims to kill Americans, and al-Qa`ida—which means the base in Arabic—had targeted U.S. interests on several occasions. It attacked U.S. military housing in Saudi Arabia in 1996, U.S. embassies in Kenya and Tanzania in 1998, and the U.S. Navy warship Cole in Yemen in 2000. Al-Qa`ida sought to drive U.S. forces from Saudi Arabia—home to Mecca and Medina, the holy cities of Islam—and from other parts of the Persian Gulf region. Many scholars believe that the group hoped to unite the Islamic world against the United States and its allies and to establish a worldwide society of Muslims governed by Shari`ah (strict Islamic law). The Taliban regime of Afghanistan hosted al-Qa`ida from 1996 until the overthrow of the regime in 2001.
Shortly after the 9/11 attacks, U.S. President George W. Bush addressed a joint session of Congress to declare a "global war on terrorism." In the nationally televised speech, Bush stated that the United States would target terrorist organizations and any government that harbored or supported them. In keeping with this policy, the United States launched a military campaign against the Taliban in Afghanistan. The support of U.S. forces enabled an alliance of Afghan rebel groups to overthrow the Taliban in December 2001. Numerous members of al-Qa`ida were captured or killed during the fighting in Afghanistan. However, many others, including bin Laden, escaped across the border to a largely ungoverned region of neighboring Pakistan.
The 9/11 attacks have had a powerful impact on the government policies of the United States and many other countries. Counterterrorism measures (efforts to fight terrorism) have become a top priority worldwide. In 2002, the U.S. government established a new executive department, the Department of Homeland Security, to coordinate efforts to prepare for, detect, respond to, and recover from terrorist activity. The government also took steps to improve security in airports and on airplanes, to increase the power of law enforcement, to address security threats from abroad, and to strengthen the nation’sintelligence (information-gathering) services.
September 11 terrorist attacks - Flight paths
On the morning of Sept. 11, 2001, the 19 Qa`ida terrorists hijacked four commercial airplanes that had departed within about 40 minutes of one another from three East Coast airports. The terrorists chose flights bound for California because the aircraft carried large quantities of fuel. The terrorists smuggled box-cutters—small tools with sharp blades—onto the planes and seized each aircraft shortly after departure. On three of the four planes, the passengers and crew did not resist, probably believing that they would be held for ransom and eventually released. However, the hijackers murdered the pilots, took control of the planes, and intentionally crashed the planes into their targets.
September 11 terrorist attacks - Ground zero
People flee collapsing World Trade Center towers
The World Trade Center. American Airlines Flight 11, bound for Los Angeles, took off from Boston's Logan International Airport at about 8 a.m. (All times of day in this article are in Eastern Daylight Time.) There were 92 people aboard. Soon afterward, at a nearby gate, United Airlines Flight 175 left for Los Angeles with 65 people.
At about 8:45 a.m., the hijackers crashed Flight 11 into the north tower of the World Trade Center. Less than 20 minutes later, their comrades flew Flight 175 into the south tower. The 110-story twin towers ranked among the world's tallest skyscrapers and were the most famous part of the World Trade Center, a complex of seven buildings. A symbol of American economic might, the World Trade Center contained offices of a number of U.S. government agencies and many businesses and organizations involved in finance and international trade. About 50,000 people worked in the complex.
As flames and smoke engulfed the towers, people raced to escape the buildings as police, fire, and medical personnel rushed to the site. About an hour after being struck, the south tower collapsed. The north tower collapsed about a half-hour later. Other buildings in the area were also destroyed or heavily damaged. The attacks left about 2,800 people dead or missing, including 157 on the two hijacked planes.
Pentagon after the September 11 terrorist attack
The Pentagon. At about 8:20 a.m., American Airlines Flight 77 left Washington Dulles International Airport in Virginia for Los Angeles. It carried 58 people. Just over an hour later, Flight 77 crashed into the west side of the Pentagon Building, the nation's military headquarters near Washington, D.C. A section of the building collapsed shortly afterward, leaving 189 people dead or missing, including the people on the plane.
Pennsylvania. United Airlines Flight 93 left Newark International Airport at about 8:40 a.m., headed for San Francisco. There were 44 people on the plane. Shortly after 10 a.m., the flight crashed in a field in Somerset County in southwestern Pennsylvania. Everyone on the plane was killed.
Telephone calls made by passengers and crew on the plane enabled investigators to reconstruct the events that led up to the crash. After the hijacking, the passengers learned of the other attacks and attempted to regain control of the plane. Afraid the passengers might succeed, the hijackers then crashed the plane into a field. Authorities believe the terrorists had planned to crash the plane into the White House or the U.S. Capitol in Washington, D.C.