Bruce Graham, the hard-driving Chicago architect of the Willis Tower, once the world's tallest building, and the John Hancock Center, the X-braced giant that became the Second City's Eiffel Tower, died last Saturday at his home in Hobe Sound, Fla., family members said. He was 84 years old.

The cause of death was complications associated with Alzheimer's disease, said his son, George.

At the peak of his influence, from the 1960s through the 1980s, the elder Mr. Graham was the top man at Chicago's biggest architectural firm, Skidmore, Owings & Merrill, and had the ear of the city's leading businessmen and politicians. From that power base, he shaped a legacy that suggests the epitaph on the tomb of Sir Christopher Wren, who is buried in his masterpiece, St. Paul's Cathedral in London: "Reader, if you seek his monument, look around you."

Besides the Willis (originally Sears) Tower and the Hancock Center, which bracket the Chicago skyline like enormous black parentheses, Mr. Graham played a major role in designing such landmark Chicago structures as the Inland Steel Building, Three First National Plaza, One Magnificent Mile and the 1986 expansion of McCormick Place.

Mr. Graham's impact extended far beyond individual designs. Though his name is often linked with the planning for the aborted 1992 Chicago World's Fair, he helped produce the visionary Chicago 21 plan of 1973, which created improvements such as the Museum Campus.

Mr. Graham's best designs gave the lean, crisp modernist look brought to perfection by Ludwig Mies van der Rohe a Chicago-style muscularity that vigorously proclaimed the structural framework of his buildings, as well as Chicago's raw industrial might.

The most prominent of them, the Hancock Center and Sears Tower, became pop icons, their dark, big-boned look featured on everything from postcards to television news sets. In one measure of its broad-based appeal, the Hancock acquired the nickname "Big John," after London's "Big Ben."

Mr. Graham's detractors, who at first included Chicago architect Stanley Tigerman (the two later became allies), called Mr. Graham a businessman rather than an artist. Others labeled him a technocrat whose buildings, especially Sears Tower, were cold and sterile. He vociferously denied all that.

Yet few disputed that Mr. Graham was the most powerful Chicago architect of his generation or that he was a leader, along with the SOM structural engineer Fazlur Khan, in shaping super-tall structures that were unthinkable to old-fashioned architects wielding T-squares.

Soaring more than a quarter of a mile into the sky, the 1,451-foot, 110-story Sears Tower epitomized Mr. Graham's technical prowess. It reigned as the world's tallest building from 1973, when construction workers raised a beam autographed by the late Mayor Richard J. Daley to the top of its structural framework, to 1996, when it lost its title to the spire-topped Petronas Twin Towers in Kuala Lumpur, Malaysia. It remains the nation's tallest building.

Looking for more from the Post-Gazette? Join PG+, our members-only web site. You'll get exclusive sports content, opinion, financial information, discounts from retailers and restaurants, and more. Our introduction to PG+ gives you all the details.