September 11, 2001 was a day that nobody will forget. It was when al-Qaeda hijacked four planes. Two were flown into the World Trade Centers.
The third plane flew into the Pentagon and the fourth was targeting the Capitol Building, but the passengers figured out something was very wrong and tried to take control back from the hijackers. Instead of hitting the Capitol, the plane crashed into a field close to Shanksville, Pennsylvania. Al Qaeda was of course responsible for the attack. They hijacked both planes and flew them into the world trade center buildings. These events killed nearly 3000 people all together.
Osama Bin Laden planned the attack because he wanted the U.S. troops out of Saudi Arabia, but we didn't get out. They were also mad at us for supporting Israel, because they think we took their land. 
It had a huge impact on airlines across the world. The airline industry lost millions of dollars and shut down for two days. Travel slowly began to resume with tighter security and new rules. Many jobs were lost in New York because many businesses were completely destroyed. The stock exchange closed down for nearly a week which caused economic crisis all over the world. Many nations offered their support to America and the War on Terrorism began.
I don't remember what I was doing on that day. I was only 3 years old.
Comments
Brief overall. Be sure to always list your sources as well.