Thirteen seasons is a long time to do anything, but "NCIS" fans are still surprised and saddened to hear that Michael Weatherly is leaving his role as Special Agent Tony DiNozzo.

TVLine said it was the actor's decision to leave the series, but the statement they shared came from CBS:

After 13 years on NCIS, Michael Weatherly is leaving the show at the end of this season. He is a valued part of the CBS family, and the immense charm and talent he brings to the screen as 'Very' Special Agent Tony DiNozzo has helped make NCIS what it is today – the No. 1 drama in the world. We thank Michael for all of his contributions to this successful franchise, and look forward to continuing to develop projects with him as part of our ongoing development deal."

While the news spread online, the actor took to Twitter to share his own announcement -- with gratitude for all the support, but no real reason for the departure:

Do you think he's just leaving to try something new? Whatever the reason, some fans now hope his character goes off to find Ziva. Is that what you want for Tony too?

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