On this day in 2001, the United States was in a state of shock after a day of attacks which left thousands dead and New York's World Trade Centre destroyed. The Pentagon was also severely damaged by one of the three civilian airliners which hijackers turned in to flying bombs. A fourth plane crashed in a field near Pittsburgh.
A state of emergency was declared in Washington D.C. and the US has closed its airspace and its borders with Mexico and Canada. American forces were on one of their highest states of alert and the Pentagon deployed a naval battle group off the country's east coast to bolster air defences.
American Airlines Flight 11 was hijacked at 0825 Eastern Daylight Time (1225 GMT) and eighteen minutes later crashed into the north tower of the World Trade Centre. United Airlines Flight 175 - which had been hijacked within minutes of the first plane - was flown into the south tower at 0903 EDT (1303 GMT) causing another devastating explosion. The second crash was captured live on news cameras trained on the burning north tower.
At 0940 EDT (1340 GMT) a third hijacked airliner - American Airlines Flight 77 - was flown into the side of the pentagon in Washington. An hour after the Boeing 767 slammed into the south tower of the World Trade Centre the 110-storey building collapsed. The north tower followed minutes later, compounding the destruction and loss of life. Witnesses reported seeing people jumping from the towers just before they collapsed.
President Bush was reading to pupils at a Florida school when his chief-of-staff whispered news of the attacks to him. He was flown to the US Strategic Command Centre at Nebraska - where the country's nuclear weapons are controlled. He was expected to address the nation later that evening.
The final number killed in the suicide attacks on 11 September was about 3,000.
To watch events unfold on that dreadful day, click the video link given below.