The CBS Building was built in 1961-64 by architect Eero Saarinen as the headquarters for one of America's three historic radio and television networks. At the height of the popularity of the steel-cage office building, Saarinen designed the CBS Building as the city's first postwar reinforced concrete skyscraper. The 38-story tower is sheathed in dark gray granite, with gray-tinted vision glass -- earning the building the sobriquet "Black Rock." Saarinen died suddenly in 1961, leaving to his office the task of supervising the construction of the building. Kevin Roche and John Dinkeloo, among others, oversaw the completion of the project.