David McCallum, known for his roles in "The Man from U.N.C.L.E." and "NCIS," passed away on September 25, 2023. His co-stars, including Lauren Holly and Michael Weatherly, expressed their sadness and support for his family. Fans also took to social media to express their love for McCallum. The official "NCIS" Instagram account and executive producers released statements honoring the actor. McCallum's death coincided with CBS' official "NCIS Day," adding to the impact of his passing. The loss of McCallum will be felt in the upcoming 21st season of the show.