David McCallum, born in 1933, was best known for his portrayal of Dr. Donald “Ducky” Mallard. His dedication to his role and extensive research made him a beloved figure until his passing at the age of 90 in 2023. Similarly, Ralph Waite, who played Jackson Gibbs, brought warmth and depth to his character. Waite, an acclaimed actor and activist, passed away in 2014 at the age of 85.