The US is marking the 17th anniversary of the 9/11 attacks that killed 2,997 people and injured more than 6,000.
Another hijacked civilian airliner crashed in a field in Pennsylvania.
The worst domestic attack the US had ever experienced, it directly led to then-President George Bush launching the ”War on Terror”, which continues to have ramifications today.
The Independent is now publishing archive images showing the immediate aftermath of the attacks.
President Bush was visiting a school in Florida when American Airlines Flight 11 crashed into the World Trade Centre’s North Tower.
The day’s planned activities were quickly abandoned as the President’s team scrambled to deal with the fallout.
As another plane hit the second tower, it became clear the collisions were not accidental.
In Washington, Vice President Dick Cheney coordinated the response in George Bush’s absence.
On the ground in New York, there was panic as the towers collapsed, flooding the surrounding neighbourhoods with dust.
The rescue effort claimed the lives of 412 emergency responders, including 343 firefighters.
To mark the 17th anniversary, President Donald Trump is scheduled to observe a moment of silence at around the time the first aeroplane hit the tower.
Meanwhile, rebuilding continues at Ground Zero. Work towards a $250m (£189m) performing arts centre continues after a design was unveiled last autumn.
Most recently, plans were announced last spring to transform a grassy clearing on the memorial plaza into a walkway and area dedicated to 9/11 rescue and recovery workers, including those who died of illnesses years after being exposed to smoke, dust and ash at Ground Zero.
This article was first published in September 2017