That gave him more pleasure, he said, than his closet full of awards and diplomas.

Above all, Bruno Thürlimann was a person of great wisdom, who recognized the importance of sustainability in engineering early on. In a major essay in 1980, based in part on a previous study by one of his former students, he called attention to the total energy requirements for producing a wide range of building materials. Comparing the energy requirements for five-meter span beams of various materials but equal strength, the study had shown as much as a 260 percent difference between the requirements for producing a steel beam and a prestressed concrete beam.

In a challenging essay, “Technology and Man,” in 1979, he called on engineers to let their technical and scientific work be guided by intelligence, reason, and humility. In his characteristic way, he foresaw that, despite how far technology had taken us, “even at the end of the 20th century, we have limited knowledge and are still bound by many errors.” In his lectures, he brilliantly separated pure mathematical derivations from the fudging of factors to fit experimental boundary conditions. He believed that “nature, as well as the human spirit, follows the path of a steady evolution,” and he cautioned that science does not protect against foolishness. He urged his listeners to always inform the public of the state of “our ignorance in making our pronouncements.”

After his retirement, Bruno enjoyed his home life, his supportive wife, Susi, and his family. He maintained informal contact with his vast network of former students, colleagues, and international body of friends from his IABSE days.

On July 29, 2008, Bruno Thürlimann died of sudden heart failure while swimming in the lake of Zurich. He is survived by his wife, Susi, two sons, one daughter, and four grandchildren.