For the well-travelled couple Iain and Julia Campbell, Australians based in San Diego at the time, the day of September 11, 2001, was just another travel day.
The couple were returning from a professional conference in Edinburgh, Scotland, where Iain, an esteemed scientist, was a participant, flying from Heathrow Airport in London direct to Chicago, on United Airlines flight UAL929, with a connecting flight to their home in San Diego.
