The core complex was built between 1966 and 1975, at a cost of $400 million (equivalent to $2.27 billion in 2021). During its existence, the World Trade Center experienced several major incidents, including a fire on , 1975, a bombing on , 1993, and a bank robbery on , 1998. In 1998, the Port Authority of New York and New Jersey decided to privatize it by leasing the buildings to a private company to manage. It awarded the lease to Silverstein Properties in .