A proposal to place the Ground Zero memorial seven stories below street level at the bottom of the World Trade Center pit would limit the size of crowds that could visit it and raises safety and evacuation concerns, security experts told The Post.
“It’s more challenging than a high-rise building in some ways [due to] the greater difficulty of getting people up, as opposed to down,” said safety consultant Jake Pauls.
“You’d have to think about it very carefully, particularly for a site that sensitive. Terrorists could pump one of the heavier gases into that area. That would cause a life-threatening situation,” he said.
Several of the proposed designs for Ground Zero include memorials in enclosed spaces below street level or in the upper floors of tall buildings.
But one of the designs – by architect Daniel Libeskind, considered to be among the front-runners for the job of Ground Zero planner – would leave most of the 70-foot-deep WTC pit open as a site for the memorial.
John Fruin, a pedestrian movement expert, said it takes about twice as long for people to walk upstairs – meaning numerous stairs would be needed to get people out quickly.
A memorial at street level could handle many more people, Fruin said.
Libeskind, whose model shows only one set of escalators entering the pit, said he discussed security issues with safety experts, and they believe his design could meet building codes.
“It could be used by a million or by one. It depends on the design of the memorial. You could either get a lot of people or a controlled number,” Libeskind said.
“How many people should the memorial hold, that’s not my job right now. My job is to provide the space for that memorial to happen . . . It’s pretty apparent this space can be made easy to work. That’s why I didn’t concentrate on that.”
In contrast, other WTC proposals stressed safety features, particularly in exiting tall buildings.