Marion Barry, the former four-term mayor of Washington, D.C. and a sitting member of the city council, died Sunday morning. He was 78 years old. His family did not specify a cause of death, though Barry had been in poor health for some time.Barry served as mayor from 1979 to 1991, and again from 1995 to 1999, with a six-month prison stay in between after he was caught smoking crack.