These stairs, now moved into the National 9/11 Memorial Museum, were the steps that hundreds took to freedom as they escaped the damage done to the Twin Towers. They remained standing above ground after the site was cleared, another final stand, but they were nearly lost to the demolition process until their symbolic value was realised.
A news report of the importance of the steps.
On 18 July 2008, they shunted these stairs from their original location and lifted by crane their 65-ton weight into the site of the new museum.
Visitors take an escalator which sits next to the 38 steps of the staircase when they arrive and leave the museum.
There’s a video of their move here: