Larry A. Silverstein is a billionaire real estate investor and operator and the head of Silverstein Properties, a real estate development group. Silverstein is also a member of New York University’s Board of Trustees. Silverstein is the developer and leaseholder of the World Trade Center towers that were destroyed in the September 11, 2001 attacks.
Silverstein became involved in real estate, together with his late father, Harry G. Silverstein, and then friend and brother-in-law, the late Bernard Mendik, buying buildings in Manhattan. In 1957, they established Silverstein Properties, as Harry G. Silverstein & Sons, and bought their first building. Other notable buildings owned by Silverstein include One River Place (42nd Street west of 11th Avenue), Two River Place, 529 Fifth Avenue, and 570 Seventh Avenue.
Source-Wikipedia
http://en.wikipedia.org/wiki/Larry_Silverstein