- The Twin Towers of the World Trade Center were built using a steel-framed structure with concrete floors and glass curtain walls. Each tower had a core that housed the elevators, stairs, and other mechanical systems, and a perimeter that contained the office floors.
- The construction of the towers was a complex and ambitious project, requiring the coordination of thousands of workers and the use of cutting-edge engineering and construction techniques.
- The North Tower was the first to be built, and it was completed in 1973. The South Tower followed, and it was completed in 1974.
- Each tower was 104 stories tall, with the North Tower rising 1,368 feet (417 m) and the South Tower rising 1,362 feet (415 m). They were the tallest buildings in the world until the completion of the Sears Tower in Chicago in 1974.
- The structural design of the towers was based on a tube system, which consisted of a series of closely spaced steel columns arranged in a square pattern. The columns were connected by steel beams, which formed a rigid framework. This framework provided the towers with their strength and stability.
- The floors of the towers were made of concrete slabs that were supported by the steel columns. The concrete slabs were pre-cast in a factory off-site, and then they were transported to the construction site and hoisted into place.
- The exterior of the towers was clad with a glass curtain wall. The glass panels were attached to the steel frame of the towers using a special type of aluminum cladding system. The curtain wall provided the towers with their distinctive reflective appearance.
- The Twin Towers were a marvel of engineering and architecture, and they stood as a symbol of American ingenuity and ambition. They were a beloved part of the New York City skyline, and their destruction in the terrorist attacks of September 11, 2001, was a devastating loss.
