9/11 was happened on September 11, 2001.19 militants associated with the Islamic extremist al -Qaeda hijacked four airlines and carried out suicide attack against targets in the United States. Two of the planes were flown into the towers of the Word Trade center in the York city,a third hit the pentagon just out the Washington D.C,and the forth plane crashed in the field in Pennsylvania.Over 3000 people were killed during the attacks in New York City and Washington D.C including more than 100 police officer and fire fighter more than 6000 were injured.