September 11 attacks
The September 11 attacks (also known as 9/11) were four terrorist attacks carried out by al-Qaeda against the United States of America. All the attacks happened on the morning of Tuesday, September 11, 2001. The attacks killed almost 3,000 people, including the 19 attackers, making it the deadliest  terrorist attack of the 21st century. They caused more than $10 billion in damage to infrastructure. The terrorists took control of 4 passenger airplanes to destroy 2 famous buildings, the Twin Towers and part of the Pentagon, by flying the planes into them. There were two attacks in New York City and one in Arlington, Virginia. The fourth attack, aimed at Washington, D.C. did not work and the plane crashed in a field near Shanksville, Pennsylvania.