Oliver Mark · CC BY-SA 4.0

A sculptor who redefined what large-scale public sculpture could be, working almost entirely in steel to make pieces that force viewers to physically move through and around them rather than simply look. He came to it sideways — an English literature degree, then years supporting himself in steel mills before art school at Yale — and that industrial material became the foundation of his career after his 1966 move to New York. His monumental, site-specific installations later placed him among the defining figures of postminimalist sculpture.