World Trade Center
A commercial complex in Lower Manhattan whose original twin towers were destroyed in the September 11 attacks and whose site was later rebuilt.
Minoru Yamasaki: An American architect known for designing the original World Trade Center and several other modernist buildings. He designed the twin towers and shaped the complex’s distinctive, closely spaced facades.
Tube (structure): A tall-building structural system in which closely spaced exterior columns and floor connections act together as a stiff tube. The twin towers used framed-tube construction to resist wind and support their height.
One World Trade Center: A 1,776-foot skyscraper that anchors the rebuilt World Trade Center complex in Lower Manhattan. It became the principal tower of the rebuilt site after the original North Tower was destroyed.
World Trade Center Transportation Hub: A transit station and public concourse designed by Santiago Calatrava at the rebuilt World Trade Center site. The hub adds a major civic and transportation function absent from the original tower-centered complex.
World Trade Center (1973–2001): The original World Trade Center complex in Lower Manhattan, dominated by two 110-story towers. This was the complex’s first major incarnation, before its destruction in 2001.
World Trade Center structural design: The structural system of the original twin towers, combining perimeter frames, a central core, and lightweight floors. Its design explains how the towers carried everyday loads and responded to aircraft impact and fire.
National September 11 Memorial & Museum: A memorial and museum at the World Trade Center site commemorating the September 11 attacks and their victims. It preserves the attack’s history and marks the footprints of the original twin towers.
7 World Trade Center: A skyscraper completed in 2006 on the World Trade Center site, replacing a building destroyed in 2001. Its reconstruction introduced new safety and sustainability features to the rebuilt complex.
Port Authority of New York and New Jersey: A bistate public agency that operates transportation facilities and develops infrastructure in the New York–New Jersey region. The agency proposed, built, and operated the original complex and led redevelopment of its site.
Elevator: A powered platform or car that transports people or goods between levels of a building. The towers’ elevator system used sky lobbies and express elevators to serve exceptionally tall buildings.