On Tuesday morning, we finished the GPS meeting in 3 WFC a little before 8:30. I walked over to 1 WTC with Brian.

I was at my desk when there was a loud crunch, the building shook violently and the lights went out. I had no idea what had happened. I could see debris falling outside the windows. People started rushing to the fire escapes. I followed the crowd. I saw Mike and Eric ahead of me but didn't recognise anybody else.

On the stairway people were calm and we moved down fairly quickly and quietly at first. A man behind me made a call on his mobile and said that we had been hit by a plane. I imaged that one of the small aircraft that you see flying around New York had hit us by accident. I think most people were thinking the same. I still didn't feel in any danger and imagined that we would all get out safely. After all, the Empire State Building was hit by a plane once.

I thought were making very good progress when I noticed that I had only reached floor 26. It's a long way down. As we got lower down we started to slow down. Every now and then we would come to a stop. A couple of people behind would shout for us to keep moving and someone in front would call for calm.

The stairs filled with the smell of smoke. I felt it in my eyes and tasted it in my mouth. Some people covered their mouths with clothing or handkerchiefs. I did this with my shirt for a few minutes expecting it to get worse but it didn't become difficult to breathe.

Water was flowing out onto the stairs around floor 10 and it ran down from there forming a little waterfall. This was what had been slowing us down. People walked more carefully. Some of the women took off their shoes. At the bottom the pool was 3 or 4 inches deep when I had to walk through.

The staircase ended at the plaza level. We were at the NorthWest corner of the tower near to the footbridge to the WFC. We were ushered out towards the door. There were fire engines lined in front of the building on the West Side Highway. To my right I could see the plaza, carpeted with wreckage much of which was burning. We were told to hurry the few paces to the entrance to the bridge by a security man who was looking up for falling debris.

There were security guards along the bridge to the WFC who instructed us to keep moving across and through to the waterfront by the marina. Looking behind I could see the thick black smoke billowing from the top of our building and flames on the other tower. I could imagine how it looked on TV and wanted to get to a phone asap to let Rebecca know I was OK.

I tried to get into Lehman-Amex building (3 WFC) to use the phone but that had been evacuated too. I searched for people with mobile phones but they were either using them or they were unable to get a line. There was a big crowd outside looking up at the burning towers. I heard people say that there had been two hijacked planes.

Looking up at the 1 WTC I could see people at the windows on the floors just beneath flames waving white flags which could have been bits of clothing or paper. All the floors above the flames were filled with thick black smoke which was coming out in all directions and forming a gigantic plume drifting up and off towards the other tower. Every now and then members of the crowd would cry out as they saw a figure jump from these upper floors.

The guards started trying to clear people away from the area so I a joined a very large queue for the ferries. The boats themselves were queued up out into the Hudson. They loaded as fast as they could and shipped people out to New Jersey. The queue was still very orderly. We parted to allow a pregnant woman through. There was even a small queue at the ticket booth. I am still trying to work out why they thought they should still be selling tickets. I only had to wait for four or five boats before I was aboard and on my way to Hoboken. This is the way I go home anyway.

There is a clear view of Manhattan from Hoboken station and a number of people were watching from there. There were fewer than ten waiting for the phone, so I joined the queue. The phones weren't working properly. I think the lines were very busy. I managed to get an operator and make a collect call home. Rebecca hadn't heard anything and was surprised to hear from me. I asked her to phone my parents. It was now about ten o'clock.

While I was on the phone I heard noise from the people outside and I guessed that the building had come down. When I went to look, I saw a cloud of dust covering the whole financial district. The taller buildings stood out above the cloud, the top of 1 WTC was still burning and there was so much smoke around the other tower that I couldn't see if it was there or not. I heard the sound of a jet overhead as I stood watching. That was one of the most worrying moments. I though something else was going to be hit. I wondered what and I wondered if we were safe where we were. Then I saw a single fighter plane appear from behind us. The plane began flying in circles around the base of Manhattan. I was very relieved to see the fighter. I felt very grateful to the pilot. I knew then that there would be no more attacks in New York.

I realised that I'd left my bag at my desk with my ticket in it. I took the 10:25 train anyway thinking that I would have to argue with the guard. I didn't. I still imagined that I would be able to collect my bag in a couple of days. The train was very crowded and stopped at every stop. I got home at about 11 o'clock.

I had no idea that both towers had collapsed or that the Pentagon had been attacked until I got home and saw the news.

I had managed to get hold of Rebecca before she'd heard anything about the attack but most of our family heard about it on the television and were very worried. Rebecca managed to speak to my parents soon after she spoke to me. My mum had been in a state of shock. After that it became very difficult to get a line for a long distance call. Rebecca's mum saw the news in a pancake house in Holland and Rebecca's Dad was in a bar in Dubai. Friends and family have been phoning and e-mailing since then to check that I was OK.