what happened on 9/11

On September 11, 2001, 19 militants associated with the 

Islamic extremist group al-Qaeda hijacked four 
airlinersand carried out suicide attacks against targets 
in the United States. Two of the planes were flown into 
the towers of the World Trade Center in New York City,
 a third plane hit the Pentagon just outside Washington
, D.C., and the fourth plane crashed in a field in 
Pennsylvania. Often referred to as 9/11, the attacks
 resulted in extensive death and destruction, triggering 
major U.S. initiatives to combat terrorism and defining 
the presidency of George W. Bush. Over 3,000 people 
were killed during the attacks in New York City and 
Washington, D.C., including more than 400 police officers 
and firefighters.it was the most terrible thing that has happened in 
new york history.