I was down in Brighton attending the annual TUC conference, so I was using his office in No 10 to hold a meeting with Martti Ahtisaari, the former president of Finland who had played an important part in the Northern Ireland peace process. Just before I went in to the meeting, I had seen pictures on TV of a plane flying into one of the twin towers but assumed it must be an accident. A few minutes in to the meeting, the duty clerk knocked on the door and said a second plane had crashed into the other tower. I said he must have got it wrong; it was just the TV rerunning the film. No, he said, it was a second plane. I abandoned the meeting, Ahtisaari excused himself and left, and Jeremy Heywood and I went into overdrive on the phones trying to make sure that no similar attack could occur in London by closing the airspace and reinforcing security in Whitehall. I spoke to Tony on the phone in Brighton; he had already decided to abandon his speech and return to No 10. He told me to get President Bush on the phone but we couldn't: he was flying around the US on Airforce One.
The frantic activity was set against the backdrop of ghastly images of the attacks on a series of TV screens on the office wall in No 10. We followed them in horror as we organised the Cobra emergency meeting of ministers and put through a series of world leaders to Tony's mobile phone as he travelled back by train.