I consider part of lower Manhattan to be hallowed ground. Nearly 3,000 people lost their lives in the World Trade Center towers... and for that reason alone, our nation should make absolutely sure that what gets built on 'Ground Zero' is an inspiring tribute to all who loved the Twin Towers, worked in them, and died there.

I will never forget the bright September day, standing at my desk in the White House, when my young assistant said that a plane had hit the World Trade Center - and then a second one - and a third, the Pentagon.

I did feel like they were telling me that something like that was going to happen. Not specifically - not that planes were going to be flown into the World Trade Center or anything like that - but in the general sense.

The real question was, here we had this information, Bin Laden intends to strike in the United States. We knew they had struck before in 1993 at the World Trade Center in the first bombing of the trade center.

The claim that the World Trade Center and the Pentagon were attacked because fundamentalists hate our prosperity and freedom is a ridiculous lie.

My wife had taken off on a plane. Two airplanes had crashed into the World Trade Center. I, of course, like any other person, felt potentially devastated, panicky a little bit.

As best I can tell there was no advance warning of the attack on the World Trade Center in 1993, which was the first significant foreign terrorist activity in the U.S. No tip-offs that it was coming.

The attacks on the World Trade Center and the current economic recession, which is particularly powerful in New York City, have put a number of building plans on hold for the time being.

Societies raise their grandest monuments to what their cultures value most highly. As the tallest buildings in a city noted for tall buildings, the Twin Towers of the World Trade Center were certainly monumental.

I had real plans for my next decade and felt I'd worked hard enough to earn it. Will I really not live to see my children married? To watch the World Trade Center rise again? To read - if not indeed write - the obituaries of elderly villains like Henry Kissinger and Joseph Ratzinger?

Notre Dame and Sydney - that was nothing. Notre Dame doesn't have a police station; it is not 1,000 or so feet high. It was a public structure, very easy to access. And Sydney Harbour Bridge was half-and-half: a bridge, in the middle of the night. The World Trade Center was the end of the world. Electronic devices, police dogs.

The difference between the Parthenon and the World Trade Center, between a French wine glass and a German beer mug, between Bach and John Philip Sousa, between Sophocles and Shakespeare, between a bicycle and a horse, though explicable by historical moment, necessity, and destiny, is before all a difference of imagination.

The truth be told, the World Trade Center was neither a very good work of architecture nor a very successful piece of urbanism. Its shortcomings were somewhat mitigated by the westward and southward expansion of the World Financial Center and Battery Park City during the 1980s.

Some words having to do with the death of the people in the World Trade Center attack had been added, and when I got to it, I had this overwhelmingly emotional experience. I struggled to get through the words; tears were streaming down my cheeks.

We live in downtown Manhattan and we have pretty big windows that looked right at the World Trade Center. I was home along with Kai and we watched it all happen. I was holding him in my arms and we were looking out the window when the second plane hit.

I was in Jersey when the whole World Trade Center thing happened and I felt powerless. So, I went to Hawaii and did a surf movie. It's kind of fluffy.

On September 11, 2001, America suffered an unimaginable tragedy and witnessed the incredible heroism of hundreds of first responders who rushed into the World Trade Center to save lives.

I think a cyber-terrorism attack is overblown, though the threat exists. I think al Qaeda and other groups are more interested in symbolic terrorism, like what they did to the World Trade Center - suicide bombers or something that really has an effect and is meaningful to people.

On the morning of September 11th, I was literally about 18 blocks from the World Trade Center. I witnessed in person what a lot of people witnessed in person, but what the world really saw on the television screen, I saw it with my own eyes that morning.

Skill is successfully walking a tightrope between the twin towers of New York's World Trade Center. Intelligence is not trying.