A monument commemorating the 9/11 tragedy was unveiled this week, after a five-year search to find it a permanent home.

Mayor Boris Johnson, historian Simon Schama and US ambassador Matthew Barzun were present as the 28-ft high sculpture, made from steel taken from the ruins of the World Trade Centre, was displayed at the Queen Elizabeth Olympic Park in east London.

Mr Johnson said: "We need to remember 9/11 in all its horror if we are truly to appreciate the values that were under threat that day."

The sculpture was commissioned in 2010 by SINCE 9/11, an educational charity chaired by Jewish businessman and JC columnist, Peter Rosengard.

He selected the steel fragments and enlisted artist Miya Ando to create the piece. "Every one of you recognises where you were on that day 14 years ago, unless you are under 14," he said.

"For any young person, they have only grown up in a 'since 9/11' world. We teach young people who were not born then in an attempt to ensure this terrible event cannot happen again."