On 11 September 2001 (known as 9/11 in America), Islamist extremists hijacked four planes that were flying above the US. Two of them were flown into the twin towers of the World Trade Center in New York. Another was crashed into the Pentagon, the top military building in the capital city, Washington DC.
On the morning of September 11, 2001, 19 al-Qaeda terrorists hijacked four commercial passenger jet airliners, intentionally crashing two into the World Trade Center in New York City. The hijackers crashed a third airliner into the Pentagon. The fourth plane crashed in a field near Shanksville, Pennsylvania.
