Fourteen years ago, on the 11th
September 2001, nearly 3,000 people were killed in a terrorist attack in the USA.
Extremists hijacked four passenger jets.
They used
two of them to destroy the Twin Towers skyscrapers of the World Trade Center, in Manhattan, downtown New York.
A third
plane crashed into the Pentagon, America's military headquarters in Washington D.C.
A fourth plane went down in fields near Pittsburgh.
As
thousands of workers scrambled to escape the burning buildings, hundreds of rescue
workers rushed to get in.
The south
tower collapsed first and then the north tower.
Around 300
firefighters were among those killed.
The group
behind the attack was Al Qaeda, an islamic terrorist organization.
America,
backed by the UK and other countries, promised to strike back.
They
launched the Afghan conflict (in October 2001); in
Afghanistan the ruling Taliban supported the organisation.
They also launched the second Iraq War (in 2003); it has
since been determined that Iraq was not linked to Al Qaeda and many think the invasion of Iraq made things worse there, not better.
In May
2011, American troops tracked down and killed Osama bin Laden, the leader of Al Qaeda.
Terror
suspects remain locked up without trial in Guantanamo, a controversial US detention
centre in Cuba.
The 9/11 Memorial to the victims was opened in 2011.
Click HERE to watch a video commemorating 9/11.
