BBC News Online: World: Americas

'It doesn't seem real'

I was on the ground floor of one of the towers at about nine o'clock in the morning when the building literally shuddered.

Because you can't begin to imagine that a hi-jacked aircraft has been deliberately crashed into a complex of buildings in which 50,000 people work, your mind immediately looks for other, reasonable explanations.

"An earthquake" went through my mind in an instant before being discounted.

At which point, people streamed through the lobby and smoke enveloped the whole area.

People weren't panicking, simply moving swiftly and determinedly for open space.

People, including myself, couldn't imagine that further danger existed.

Flames and smoke

You can't imagine the reality of it all - so we stayed put, simply looking up at the first tower that was struck.

Flames and smoke were appearing from the top.

As people looked, the second aircraft emerged in the bluest of skies and simply tore straight into the second tower.

People then fled further - but still not far enough.

There were long lines of ambulances stretched up to the site of the World Trade Center.

And that appears to have been part of the problem.

People assumed the buildings themselves wouldn't collapse - a false and fatal assumption.

Hundreds of firefighters are now known to have died. Many police officers are also known to have died.

At the end of it all, the enormity of the event still doesn't sink in.

Even when I see pictures of the plane crashing into the building, it doesn't seem real

It looks like a toy plane crashing into a toy building.

It wasn't.