'Survivor's staircase' moved from Ground Zero
The “Survivor's Staircase” was not damaged when the buildings in New York's Lower Manhattan collapsed. The stairs have remained on the site ever since.
They are being moved to make way for a a new building, but will become part of the September 11 Memorial close to Ground Zero.
The Twin Towers of the World Trade Centre collapsed in September 2001 when they were hit by two passenger planes flown by al-Qaeda terrorists. Nearly 3,000 people lost their lives in the attacks.