Art Gensler with the LAFC Performance Center and Shanghai Tower (Credit: Courtesy of Gensler, Emily Hagopian, Blackstation) M. Arthur Gensler Jr., who for decades led one of the world’s most prolific architecture firms, died at his home in Mill Valley, California. He was 85. Gensler, the firm he co-founded in 1965 with his wife, Drue, and architect James Follett, announced the news Monday. No cause was given. In the decades since the firm’s founding, Gensler has completed numerous high-profile projects, including the 128-story Shanghai Tower, currently the world’s second-tallest building; and Banc of California stadium in Los Angeles. But much of its work was less buzzy. When the Genslers started the firm, they focused largely on interiors, with San Francisco’s Alcoa Building and 555 California Street — both designed by Skidmore, Owings & Merrill — among its earliest projects.