World Trade Center
The First Round
The building of the world trade centers began in 1968. Originally the first set of towers were going to be 80 stories tall, but to fulfill the requirements for square footage, they needed to make the buildings 110 stories tall. Overtime the structure needed repair, to maintain the strength of the building.
The New Center
The new world trade center was put in process started in 2006. After 5 years of clean up after the attack the building of the new trade centers started. They hired 101 contractors and sub-contractors. In order to complete this they would build one full office floor each week. The new center contains an elevator that takes 45 seconds to get from bottom to top. Total the building of the new center costs $3.6 billion to build.
The 9/11 memorial was built in the footprints of the twin towers. Each are built 30 ft down, man made. On the memorial's are the names of each person that has died in the 1993 attack as well as 2001. The cost of building the memorial costed $2 Billion. With the cost of the towers being more than that.