 At the time of the September 11 , 2001 , attacks , Salomon Smith Barney was by far the largest tenant in 7 World Trade Center , occupying 1 @,@ 202 @,@ 900 sq ft ( 111 @,@ 750 m2 ) ( 64 percent of the building ) which included floors 28 – 45 . Other major tenants included ITT Hartford Insurance Group ( 122 @,@ 590 sq ft / 11 @,@ 400 m ² ) , American Express Bank International ( 106 @,@ 117 sq ft / 9 @,@ 900 m ² ) , Standard Chartered Bank ( 111 @,@ 398 sq ft / 10 @,@ 350 m ² ) , and the Securities and Exchange Commission ( 106 @,@ 117 sq ft / 9 @,@ 850 m ² ) . Smaller tenants included the Internal Revenue Service Regional Council ( 90 @,@ 430 sq ft / 8 @,@ 400 m ² ) and the United States Secret Service ( 85 @,@ 343 sq ft / 7 @,@ 900 m ² ) . The smallest tenants included the New York City Office of Emergency Management , National Association of Insurance Commissioners , Federal Home Loan Bank , First State Management Group Inc . , Provident Financial Management , and the Immigration and Naturalization Service . The Department of Defense ( DOD ) and Central Intelligence Agency ( CIA ) shared the 25th floor with the IRS . Floors 46 – 47 were mechanical floors , as were the bottom six floors and part of the seventh floor . 
