on june 25, 2012, steel topped out at floor 72. structural steel and concrete completed by june 1, 2013, followed by the removal of construction fencing in september 2013 and the building's opening on november 13, 2013. cost of construction of 4 world trade center was us$1.67 billion, funded by insurance funds and liberty bonds. the first tenants to move in were two government agencies, and , the building is 62% leased.