Structural engineer Daniel A. Cuoco, former president and CEO of Thornton-Tomasetti, died of cancer on Sept. 21. He was 68 years old.

He joined the New York City-based firm in 1971, when it was named Lev Zetlin Associates. He became president in 2002 and president and CEO in 2008. He retired in 2011.

In the mid-1980s, Cuoco formed LZA Technology, the firm's structural forensics arm. After the World Trade Center attacks, he identified this work as his most important job, say his colleagues. Beginning on Sept. 11, 2001, Cuoco led a team of engineers who oversaw rescue efforts and later cleanup operations in the unstable debris field (ENR 9/24/01 p. 10).

"Dan worked tirelessly in the immediate aftermath of 9/11 to mobilize the engineering community and, later, in defending their interests and advocating for reform, such as the need for a 'good Samaritan law,' " says Thomas Z. Scarangello, chairman and CEO of the 850-person Thornton Tomasetti (TT). "He had an unshakable ethical compass, [always] working to raise the bar of best practice."

Cuoco's first high-profile investigation was the construction collapse of the L'Ambiance Plaza apartment building in Bridgeport, Conn., where 28 workers died (ENR 4/30/87 p. 10).

Another prominent investigation and emergency structural stabilization job was triggered by the 1998 hoist collapse at Manhattan's Four Times Square high-rise. A woman was killed in her top-floor apartment as the 700-ft-tall hoist mast came crashing through her ceiling (ENR 8/10/98 p. 10). Cuoco also led an investigation into the 1999 crane collapse at Milwaukee's Miller Park, which killed three ironworkers (ENR 7/26/99 p. 12).

David B. Peraza, a principal engineer at Exponent who worked with Cuoco at TT for 22 years, remembers his mentor as honest, fair and good-natured, saying, "He would hire good people, challenge them and trust them to do a good job."