A staircase people used to escape the World Trade Center during the Sept. 11, 2001, attack has been moved for a second time on the ground zero site.

The 22-foot-high survivors' staircase was moved Saturday from
the northwest corner of the site into a seven-story pit closer to
the memorial.
Authorities say they plan to install the staircase at
the entrance to the Sept. 11 museum.
The staircase had been the last aboveground remnant of the
original trade center complex after the terrorist attacks.
It wasfirst moved in March to make way for a new skyscraper.

Preservationists and survivors lobbied for years to not move the
staircase at all.