In 1971, Kohlberg was working in Belize when he contracted a parasitic infection. As a result of the disease, Kohlberg spent the next sixteen years of his life battling depression and constant, debilitating pain. On January 19th, 1987, Kohlberg requested a day of leave from the hospital where he was undergoing treatment. After leaving the hospital, Kohlberg drowned himself in Boston Harbor. He was fifty-nine years old.