Preservationists and survivors had lobbied for years to not move the staircase it all, or at least keep its 37 stairs intact. The stairway had been part of the original trade center plaza, giving survivors a safe way out to a nearby street before the towers collapsed.
Rebuilding officials agreed to install the staircase at the entrance to the Sept. 11 museum.
The staircase had been at street level for the last couple of months, on the northwest corner of the site. On Saturday a crane lifted it to a place closer to the memorial and lowered it into the seven-story pit.
