'Once-Lowly' Piece of Infrastructure Honored as a Hero of 9-11

After it was built over nine months beginning in 1967 "using jury-rigged tools, on a site that brimmed with uncharted obstacles and unhappy surprises", engineer Arturo Lamberto Ressi di Cervia never thought he'd see the retaining wall he helped construct again in his life. But the events of Sept. 11, 2001 changed that. 

"Because the slurry wall held, the 70-foot-deep foundation did not fill with groundwater [when the towers fell]. And because of that, the PATH tubes were not submerged. And because of that, the subway tunnels below the PATH tubes were not inundated," explains Dunlap. "How much worse could Sept. 11 have been? Imagine if Hurricane Sandy had followed the terrorist attack by a few hours."

"Thirty-five years later, in 2002, the architect Daniel Libeskind drew the world’s attention to the symbolic significance of the wall, when he proposed its preservation and exposure as part of the redevelopment of the trade center."