Mark Harmon’s Touching Tribute to David McCallum: ‘I Was in Awe When I First Met Him’

Mark Harmon is expressing his condolences following the passing of his long-time NCIS co-star David McCallum, who died at the age of 90 on Monday.

“David lived a great, full, long life,” Harmon shared in a statement to TVLine. “I was in awe when I first met him, and all of us on the show were honored to have toed a mark opposite him. My condolences go out to Katherine and his family.” (Read more tributes from McCallum’s NCIS co-stars past and present here.)

As we reported, McCallum — who most recently appeared, remotely, in the final two episodes of NCIS‘ 20th season last spring — passed away at New York Presbyterian Hospital of natural causes. With Harmon’s exit from NCIS in Season 19, McCallum was the CBS procedural’s last original cast member.

“For over 20 years, David McCallum endeared himself to audiences around the world playing the wise, quirky, and sometimes enigmatic, Dr. Donald ‘Ducky’ Mallard,” said NCIS‘ current exec producers, Seven D. Binder and David North, in a statement. “But as much as his fans may have loved him, those who worked side by side with David loved him that much more. He was a scholar and a gentleman, always gracious, a consummate professional, and never one to pass up a joke. From day one, it was an honor to work with him, and he never let us down. He was, quite simply, a legend. He was also family and will be deeply missed.”

Added a CBS spokesperson: “We are deeply saddened by the passing of David McCallum and privileged that CBS was his home for so many years. David was a gifted actor and author, and beloved by many around the world. 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. We will miss his warmth and endearing sense of humor that lit up any room or soundstage he stepped onto, as well as the brilliant stories he often shared from a life well-lived.”