Sears Tower designer dies of complications

Bruce J. Graham, designer of the former world's tallest building and the existing tallest building in the United States, has died at the age of 84.

Chicago-based public relations firm SCC Grossman said Monday that the designer died on Saturday of complications associated with Alzheimer's disease.

The 110-storey building in Chicago, designed by Graham and known as the Sears Tower when it opened in 1974, remained as the world's tallest until the Petronas Twin Towers were opened in 1996 in Kuala Lumpur of Malaysia.

The Chicago skyscraper was renamed the Willis Tower in 2009.

Graham also designed Chicago's 100-storey John Hancock Center building.