September 11 attacks
On the World Trade Center site, three more office towers were supposed to be built one block east of where the original towers were. 7 WTC was the first to open on May 23, 2006 after four years of construction. 4 WTC was the second tower to open on November 13, 2013. 3 WTC opened on June 11, 2018 making it the fourth skyscraper at the site to be finished.