On Sept. 11, 2001, 19 terrorists took over four planes and attacked the United States, according to History.com. Two of the planes hit the twin towers of the World Trade Center in New York City, one crashed into a field in Pennsylvania and one hit the Pentagon in Washington D.C.
Close to 3,000 people died in the terrorist attacks. The first plane hit the north tower early in the morning and left a hole in the 80th floor of the building, leaving many people stuck on higher floors. Almost 20 minutes later, a second plane hit the 60th floor of the south tower. The terrorists were from Saudi Arabia and nearby countries and were associated with Osama bin Laden and al-Qaeda. After the planes crashed into the towers, the towers collapsed, killing and injuring many people in the buildings and around them.
The Pentagon attack killed 125 people, including many military members as well as all of the people that were on the plane. The intended location of the fourth plane is unknown because people on board fought the attackers after hearing about the other terrorist attacks. The plane flipped over and plummeted toward the ground at a rapid speed, killing all of the people on board when it crashed in a Pennsylvania field.