World Trade Center History (part 1 of 2): The twin towers of the World Trade Center were more than just buildings. They were proof of New York's belief in itself. Built at a time when New York's future seemed uncertain, the towers restored confidence and helped bring a halt to the decline of lower Manhattan. Brash, glitzy, and grand, they quickly became symbols of New York. Rockefeller Brainchild The World Trade Center was conceived in the early 1960s by the Downtown-Lower Manhattan Development Association to revitalize the seedy “radio row” dominated by electronic stores. Chase Manhattan Bank chairman David Rockefeller, founder of the development association, and his brother, New York governor Nelson Rockefeller, pushed hard for the project, insisting it would benefit the entire city. In 1962, the Port Authority of New York and New Jersey began plans to build the center. Minoru Yamasaki and Associates of Michigan was hired as architect. Eventually, Yamasaki decided on two huge towers. Critics charged that a modern monolith would rob New York of character, ruin the skyline, disrupt television reception, and strain city services. However, the project was approved and construction began in 1966. In order to create the 16-acre World Trade Center site, five streets were closed off and 164 buildings were demolished. Construction required the excavation of more than 1.2 million cubic yards of earth, which was used to create 23.5 acres of land along the Hudson River in lower Manhattan. During peak construction periods, 3,500 people worked at the site. A total of 10,000 people worked on the towers; 60 died during its construction. Instant Landmarks The north tower was opened in Dec. 1970 and the south tower in Jan. 1972; they were dedicated in April 1973. They were the world's tallest buildings for only a short time, since the Sears Tower in Chicago was completed in May 1973. However, the towers were ranked as the fifth and sixth tallest buildings in the world at the time of their destruction on Sept. 11, 2001. Four smaller buildings and a hotel, all built nearby around a central landscaped plaza, completed the complex. The mall at the World Trade Center, which was located immediately below the plaza, was the largest shopping mall in lower Manhattan. The six basements housed two subway stations and a stop on the PATH trains to New Jersey. Some 50,000 people worked in the buildings, while another 200,000 visited or passed through each day. The top floor observation deck had 26,000 visitors daily, who could see for 45 mi on a clear day. From the ground, the towers were visible for at least 20 mi. The complex had its own zip code, 10048. Previous Bombing In 1993 terrorists drove a truck packed with 1,100 lbs of explosives into the basement parking garage at the World Trade Center. Despite the size of the blast—it left a crater 22 ft wide and five stories deep—only six people were killed and 1,000 injured. The towers were repaired, cleaned, and reopened in less than a month. September 11, 2001 On the morning of September 11, 2001, terrorists from al-Qaeda hijacked four planes. Two were Boston-to-Los Angeles flights, which the hijackers diverted to New York City. At 8:45 a.m., American Airlines Flight 11 was flown into the north tower of the World Trade Center. Eighteen minutes later, United Airlines Flight 175 was flown into the south tower. Each plane was loaded with sufficient jet fuel for its intended cross-country trip, which ignited upon impact, creating intense fireballs in both towers and weakening the structural integrity of each. At 9:50 a.m., the affected floors of the south tower gave way; the upper floors collapsed onto the lower ones, destroying the tower and crushing everyone who was still inside it. At 10:29 a.m., the same happened to the north tower. 2,824 people were killed in the attacks, including hundreds of firefighters and other rescue workers. (Of the other two hijacked planes, one was crashed into the Pentagon; the other crashed southeast of Pittsburgh, apparently as a result of its passengers fighting the hijackers. There were no survivors.)