Vanderbilt's fourth marriage was to author Wyatt Emory Cooper, on December 24, 1963. The marriage, which lasted 15 years, ended with his death in 1978 while he was undergoing open-heart surgery. They had two sons: Carter Vanderbilt Cooper (January 27, 1965 – July 22, 1988), who committed suicide or was the victim of medication that precipitated a psychotic episode at age 23 by jumping to his death from the family's 14th-floor apartment, and Anderson Hays Cooper (born June 3, 1967), a CNN news anchor.