NEW YORK (AP) - Hundreds of workers are busy around the clock constructing the $4 billion World Trade Center transportation hub.
The complex will include PATH trains to New Jersey, and links to New York City subway lines when it opens in 2015.
The design by Spanish architect Santiago Calatrava features two white sections that look like wings. It is designed so that each Sept. 11, sunlight will directly hit a skylight between them at exactly 10:28 a.m. _ the time when the second tower collapsed.
High above the hub is the 104-story 1 World Trade Center. And right above the underground complex lies the 9/11 Memorial plaza.
Construction director Steven Plate said during a tour Wednesday it's more than an engineering feat. He says the project is meant to "remember the souls of nearly 3,000 people" who died there.
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