On 9 September 2001, Islamic terrorists launched a massive attack on the USA.
In an act that would come to define the early 21st century, terrorists hijacked four passenger planes, flying two of them into the World Trade Centre buildings in New York, and one into the Pentagon in Washington DC. The fourth plane crashed before reaching its target.
Nearly 3,000 people died as the World Trade Centres collapsed, shocking America into a state of emergency and putting them on a collision course with the Islamic world for years to come.
Watch original British Pathe footage from the 9/11 attacks, above.