Cushman & Wakefield's Joe Stettinius, a commercial real estate veteran who became the firm's CEO of Americas after its merger with DTZ, died Thursday at 55. Stettinius reportedly died of a heart attack at his farm in Upperville, according to the Washington Business Journal. He is survived by his wife, Regina, and two children, Alexander and Isabelle. After helping launch Cassidy Turley in 2010, he oversaw the firm's merger with DTZ in January 2015. DTZ then merged with Cushman & Wakefield to form a 43,000-employee global giant, with Stettinius as CEO of Americas. Stettinius later switched roles to become chief executive of brokerage and capital markets, followed by executive vice president of strategic investments.