As our trawl through the archives discovered,it was alsothe year 20-year-old Aussie tennis player Lleyton Hewitt won the US Open,beating America’s Pete Sampras just two days before the Twin Towers came down.

Twenty years on,watchingthis incredible compilation by our video journalist Tom Compagnoni makes that week seem far more recent;at the same time the whole event still seems surreal.

There were an estimated 17,400 people in the 110-storey buildings when the planes struck. It took less than two hours for the twin monoliths to collapse onto their vast footprints,sending piles of twisted rubble hundreds of metres across Manhattan. In total 2977 people were killed,including 412 first responders who entered the buildings to help those trapped on the upper floors. That also included those from the third plane that struck the Pentagon,outside Washington DC,and a fourth that crashed in Pennsylvania because brave passengers overpowered the hijackers.

Thousands more people sustained significant injuries in the attacks or later contracted illnesses connected to it - and the emotional scars for those left behind are all too real. Citizens from 77 countries were among the casualties.