David McCallum, known for his role as 'Ducky' on 'NCIS,' has died. He was 90. The actor began his television career in the 1950's and rose to stardom for his role in the 1964 British series 'The Man From U.N.C.L.E.' David then starred in 'NCIS' for twenty seasons and became the longest-standing member of the original cast.