in the early 1970s, simonton had an emergency operation for complications of appendicitis; the operation went wrong and he suffered brain damage as a result. he spent several years struggling to regain full command of basic skills, including control of his speech. at this point, he largely retired from public life, although in time he was able to continue his love of travel and his wide community of friends. he died in 1979 from a heart problem, likely related to the damage sustained in the operation.