Designer of Chicago's John Hancock and Willis Tower (formerly the Sears Tower) buildings died Saturday at his home in Florida at the age of 84. Howie alerted me to this story about the American Architect Bruce Graham. The Willis Tower, which was renamed last year for a British insurance brokerage, remains the tallest building in the United States. The 110-story, 1,451-foot skyscraper reigned as the world's tallest building from 1973 to 1996, when it lost its title to the Petronas Twin Towers in Kuala Lumpur, Malaysia. Taller structures have since been erected. He designed another iconic Chicago landmark, the John Hancock Center. Unlike earlier skyscrapers, in which an internal cage of steel carried most of the load, the Hancock's exterior beams and X-shaped braces formed a rigid tube that did most of the heavy lifting. The arrangement was economical and the X-braces offered an instantly recognizable skyline image, silencing detractors who had likened the Hancock to an oil derrick. For the majority of his career, he headed the Chicago office Skidmore, Owings and Merrill, the largest architectural firm in the United States. He was deeply involved with many aspects of developing the city of Chicago, from city planning, bringing great public art to the city and involvement in individual projects.