'NCIS' Actor David McCallum Dead at 90

Veteran actor David McCallum, most famous for playing medical examiner Dr. Donald 'Ducky' Mallard on the hit TV show "NCIS," is dead.

David died Monday at New York Presbyterian Hospital, the result of natural causes ... according to a statement from CBS.

The network is remembering David as "a gifted actor and author, and beloved by many around the world."

CBS also says of David ... "He led an incredible life, and his legacy will forever live on through his family and the countless hours on film and television that will never go away."

David appeared in more than 400 episodes of "NCIS" on CBS ... and he was also known for his work on the 1960s TV show "The Man from U.N.C.L.E." ... earning nominations for Emmys and Golden Globes.

In addition to his work in TV, David also landed roles in movies ... including "The Great Escape," "A Night to Remember," "Mosquito Squadron," "Freud," and "The Greatest Story Ever Told."

David is survived by his wife of 56 years, his three sons, his daughter, and his eight grandkids.

CBS says an upcoming 20th anniversary "NCIS" marathon will add an "In Memoriam" for David.

He was 90.