When plans for the world trade centre were first revealed in January 1964, the structure was set to cost $330 million. By the time construction was completed in 1973, the costs to Port Authority had reached $900 million.
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Even before construction was completed, the twin towers had appeared in movies The French Connection and The Hot Rock.
They captured global audiences when King Kong scurried up the side of the south tower, and in 1974 when French daredevil Philippe Petit walked between the towers on a tightrope.
In 1993, the towers were attacked for the first time when a truck loaded with explosives detonated in the parking lot of the North Tower building. The attack claimed six lives. And on September 11, 2001 two hijacked planes were flown into the the twin towers. The attacks killed 2,753 people in all and left a gaping hole in New York city’s skyline.
In 2006, the site began being prepped for construction again. Port Authority continues to control Freedom Tower and Tower 5, while Silverstein Properties controls Towers 2, 3 and 4. This time around, the entire World Trade centre project is estimated to cost $19 billion, while the cost for Silverstein Properties buildings are $7 billion.
A view of a construction worker as he works on the World Trade centre building in New York City, 1970
Construction workers raise their hats in salute as the American flag is attached to a steel column which is hoisted to the top of the north tower building of the World Trade centre, December 23, 1970
A construction worker guides a steel beam for the formal topping out ceremony of the south tower, July 19, 1971
French tight rope walker Philippe Petit balances as he walks between the World Trade centre. When he was done police officers took him into custody, August 7, 1974
The crater and surrounding wreckage at the site of the World Trade centre towers after the terrorist attacks, September 2001
The construction site by night with light beams from the Empire State Building in the background, September 2008
Visitors to the World Trade centre look at the rising steel frame of 1 World Trade centre, December 2009
Construction cranes work on the 56th floor of One World Trade centre, centre, February 2011. The tower will rise to 104 floors when completed in 2013
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