Rebuilding after 9/11

After the 9/11 terror attacks in New York, the city was left with a gaping hole in its skyline.

In its place the tallest skyscraper in the USA was built.

TJ Gottesdiener was one of the architects who worked on One World Trade Center.

He's been speaking to Witness.

Witness: The stories of our times told by the people who were there.