Both towers of the World Trade Center were leased to Larry A. Silverstein for more than $3 billion back in 2001. By that time annual income of the towers was $200 million.
Specially for the 11th of September, 2011, Silverstein and the board members of the company had planned a meeting on the 88th floor. The purpose of the meeting was to discuss what to do in the event of a terrorist attack. However the meeting was canceled and rescheduled because on of the members was not able to attend it.