In what season does Derek Shepherd die?

Derek Shepherd dies in season 11 of Grey's Anatomy. His death occurs in the episode “How to Save a Life,” which originally aired in April 2015.

After helping people at the scene of a car crash, Derek is struck by a truck while stopped on the roadside. He is taken to a hospital that lacks the specialists and equipment needed to treat his severe injuries. Although he remains conscious for part of the sequence, critical delays and medical errors prevent effective treatment.

Derek's death is a major turning point for Meredith Grey, his wife, and for the series as a whole. Patrick Dempsey, who played Derek from the show's beginning, left the regular cast after the episode. The event is sometimes confused with earlier near-death storylines, including Derek's season 9 plane-crash injuries and season 10 complications, but neither of those episodes is his death. The character's final appearance also made season 11 one of the show's most consequential seasons.