Tomorrow will mark twenty years since two airplanes hijacked by terrorists were flown into the World Trade Centre in New York on September 11, 2001.

Almost 3000 people died, including ten Australians.

Then 44-year-old Joe Dittmar was on a business trip in a meeting on the 105th floor of the South Tower when the first plane hit the North Tower.

Remarkably, Mr Dittmar was 74 floors up when the second plane hit.

Press PLAY to listen to his unbelievable story below