Charles Thornton—renowned structural engineer, educator, mentor, and founding principal of Thornton Tomasetti—died on December 12, 2023 in Maryland after a brief illness. He was 83. Known by friends and family as “Charlie,” Thornton is remembered for having worked on some of the world’s most recognized buildings. He retired from his role as chairman and CEO of Thornton Tomasetti in 2004.

“Charlie was a visionary, foreseeing the needs of structural engineering, our clients, the building industry and the public it serves,” said Richard Tomasetti, founding principal of Thornton Tomasetti, in an obituary the engineering firm shared on its website. “He was equally dedicated to mentoring everyone in our firm, our partners, and future generations through his founding of the ACE Mentor Program of America. I am fortunate to have had Charlie as my partner and friend for more than 60 years and to have shared in his inspiring journey that helped people achieve more than they ever imagined.”

Thornton was born in 1940 and grew up in the Bronx. He credits his father—an electrician and bricklayer who later served as the Bronx’s chief building inspector—for inspiring him to become an engineer. Later, Thornton earned a bachelor’s degree in civil engineering from Manhattan College and master’s and doctoral degrees from New York University. As a doctoral student, he met Lev Zetlin in his research about double-layer bicycle wheel roof systems.

In 1960, Thornton joined Lev Zetlin Associates where he embarked on work for multiple pavilions for exhibition at the 1964 World’s Fair in New York. There, Thornton also worked on impressive projects like the American Airlines 747 SuperBay hangars in San Francisco with SOM’s Myron Goldsmith—a feat that required orthotropic steel decking in hyperbolic paraboloid configurations as webs for expansive roof cantilevers.

Richard Tomasetti and Charles Thornton started Thornton Tomasetti in 1983, one of the world’s most respected multidisciplinary engineering firms. But Thornton is remembered for his engineering brilliance as well as his philanthropy.

Over the course of his sixty year career, Thornton received numerous accolades, among this induction into the National Academy of Engineering and the National Academy of Construction and an honorary membership in the American Institute of Architects and American Society of Civil Engineers. Alongside Richard Tomasetti, he is the recipient of the Council on Tall Buildings and Urban Habitat’s Fazlur R. Khan Lifetime Achievement Medal.

Thornton founded ACE Mentor Program in 1994, a nonprofit that introduces high school students to careers in architecture, construction, and engineering. Each year, more than 10,000 students and 4,000 mentors partake in the program. In 2011, ACE Mentor Program was recognized by President Barack Obama with the Presidential Award for Excellence in Science, Mathematics and Engineering Mentoring.

Aside from his professional and philanthropic contributions, Thornton is also remembered as a devoted husband, father, grandfather and great-grandfather. An avid sailor and painter, Thornton named his sailboat “An Elegant Solution.”

In his memoir, A Life of Elegant Solutions, Thornton said: “Engineering, at its core, is about shaping the future. It is through our collective efforts that we have the power to create structures that not only stand tall but also stand as reminders of human ingenuity.”