The World Trade Center (WTC) was a 7-building complex that stood in Lower Manhattan in New York City. Construction on it began in 1966 and finished in 1987. The Twin Towers were destroyed when 2 planes hijacked by terrorists slammed into them at speeds of 490 to 590 mph, eventually causing the Towers to collapse and destroying the other 5 buildings. Currently, the site is becoming home of the new World Trade Center and the National September 11 Memorial & Museum. The complex was designed by architect Minoru Yamasaki in the 1960s using a tube-frame structural design for the Twin Towers.