Constructed by the Port Authority of New York and New Jersey in the early 1970s, the World Trade Center towers were, for their time, the best known examples of tube buildings.
Description
The two towers were unable to survive the effects of a direct hit by two hijacked commercial jetliners during terrorist attacks on the morning of September 11, 2001. Although they were in fact designed to withstand being struck by an airplane, the resultant fires weakened the infrastructure of the building, collapsing the upper floors and creating too much load for the lower floors to bear. Shortly after the attack, both towers collapsed.