Survivors ' Staircase was the last visible remaining original structure above ground level at the World Trade Center site . It was originally two outdoor flights of granite-clad stairs and an escalator that connected Vesey Street to the World Trade Center 's Austin J. Tobin Plaza . During the September 11 attacks , the stairs served as an escape route for hundreds of evacuees from 5 World Trade Center , a 9-floor building adjacent to the 110-story towers . The staircase is now an important feature of the National September 11 Memorial & Museum
September 11 attacks
September 11 attacks
Survivors' Staircase