The BBC College of Journalism website is publishing a series of posts offering personal memories of coverage of the 9/11 attacks. The first, published this week, is by Stephen Evans, now Berlin correspondent for the BBC, who was in the World Trade Centre when the first plane hit.

I can remember looking out and seeing a line of neat fire trucks and thinking everything was OK because the authorities had arrived. I was on the air – I think to News 24 – when the North Tower collapsed, cutting the line off. I can remember ranting at this. The hotel alarm went off and we evacuated down a back stairs in an orderly fashion.

Evans was on the air when the South tower, the first of the two to collapse, began to fall: