Grey's Anatomy has never been shy about killing off a main character, either for story purposes or to fulfill an actor's wish to leave the series. But the death that still resonates in everyone's mind is that of Derek Shepherd (played by Patrick Dempsey). His loss marked a milestone for the medical drama, reminding audiences that no one is safe in the eyes of creator Shonda Rhimes.
Source：https://www.cbr.com/what-episode-greys-anatomy-derek-dies/
