David McCallum, best known for his role as Ducky on NCIS, has passed away at the age of 90. McCallum portrayed the eccentric chief medical examiner for the first 15 seasons of the show. He was a beloved actor and author, and his legacy will live on through his family and his work on film and television. McCallum's departure from NCIS in season 15 was met with sadness from fans, but his character will always be remembered. He had a celebrated career beyond NCIS, including his role in The Man From U.N.C.L.E and various film roles.