NEW YORK — Thirteen years after the 9/11 terrorist attack, the resurrected World Trade Center is again opening for business — marking an emotional milestone for both New Yorkers and the nation.

Publishing giant Conde Nast will start moving today into One World Trade Center, a 104-story, $3.9 billion skyscraper that dominates the Manhattan skyline. It is America’s tallest building.

It’s the centerpiece of the 16-acre site where the decimated twin towers once stood and where more than 2,700 people died on Sept. 11, 2001, buried under smoking mounds of fiery debris.

“The New York City skyline is whole again, as One World Trade Center takes its place in Lower Manhattan,” said Patrick Foye, executive director of the Port Authority of New York and New Jersey that owns both the building and the World Trade Center site.

He said One World Trade Center “sets new standards of design, construction, prestige and sustainability; the opening of this iconic building is a major milestone in the transformation of Lower Manhattan into a thriving 24/7 neighborhood.”