Corley's daughter, Anne Baum, told the Chicago Tribune he died Friday of cancer in the Midwest Palliative and Hospice CareCenter in Glenview, Ill. He was 77.
A native of Shelbyville, Ill., Corley said he was attracted to engineering because of his father's work as a construction contractor. He ended up with a bachelor's, a master's and a doctoral degree in engineering, all from the University of Illinois.
In addition to heading the federal investigation into the fall of the Twin Towers on Sept. 11, 2001, Corley investigated the gutting of the Branch Davidian compound in Waco, Texas, during a 1993 FBI raid and the 1995 bombing of the Oklahoma City federal building. At the time of his death, he was senior vice president with the CTLGroup in Skokie, Ill.
"Gene was a pioneer in what is commonly known as forensic structural engineering," said Jeffrey Garrett, the CTLGroup's president and chief executive officer. "He investigated all sorts of building distress, building failures, structural failures of all kinds. He was tireless."
Corley began his career with the U.S. Army Corps of Engineers. He then went to work for the Portland Cement Association, an industry group, and joined CTL when it was spun off as a for-profit company.