On September 11th, 2001, the United States of America was attacked by terrorists. Four aircraft were hijacked. Two, American Airlines Flight 11 and American Airlines Flight 175, were crashed into the World Trade Center. One, American Airlines Flight 77, crashed into the Pentagon, and one, United Airlines Flight 93 was taken over by passengers and crashed in a field in Shanksville, Pennsylvania while nearing Washington D.C. Nearly 3000 people were killed.
