Less than five years ago, Daniel Libeskind held a press conference in the north German town of Osnabruck. It was a small event in global terms - the opening of a provincial art gallery. But the international media arrived in numbers. This was Danny's first completed building. It was also a memorial, devoted entirely to the work of the artist and Holocaust victim Felix Nussbaum. Libeskind was already getting famous, thanks to his extraordinary competition-winning design for the Jewish Museum in Berlin, a jagged lightning-bolt of a building unlike anything architecture had previously seen. But none of us there in Osnabruck that summer could have predicted where all this was to lead. On Thursday 27th February, Libeskind won the biggest, most prestigious and most sensitive architectural commission in the world, for a project worth in total many billions of dollars: to rebuild the World Trade Center site at Ground Zero in Manhattan.