<P> "How to Save a Life" is the twenty - first episode of the eleventh season of the American television medical drama Grey's Anatomy, and is the 241st episode overall . It aired on April 23, 2015 on ABC in the United States . The episode was written by showrunner Shonda Rhimes and directed by Rob Hardy, making it the first episode Rhimes has written since the season eight finale "Flight". The installment marked the death and final appearance of the series' male lead character, Derek Shepherd (Patrick Dempsey), who had starred on the series since its inception . </P> <P> In this episode, Shepherd is involved in an accident while attempting to help the victims of a car accident . He is later pronounced brain dead, in part due to the surgeons not providing him with a timely CT scan . Only six regular cast members--Ellen Pompeo, Patrick Dempsey, Chandra Wilson, Kevin McKidd, Sarah Drew and Caterina Scorsone--appear in the episode . "How to Save a Life" also marks the first appearance of Dr. Penelope Blake (Samantha Sloyan). </P> <P> The episode's original broadcast was watched by 9.55 million viewers and registered the show as the week's highest - rated drama and third - highest rated scripted series in the 18--49 demographic . It received mixed reviews from the critics who were divided on the show's handling of Shepherd's death . However, they were largely laudatory of Pompeo, with critic Rick Porter deeming it the best performance of her career . </P> <P> The episode opens with a flashback of a five - year - old Meredith Grey (Ellen Pompeo) lost in a park . In the present, Dr. Derek Shepherd (Patrick Dempsey), is on his way to Washington to resign from the President's brain mapping project . He witnesses a road accident and pulls over to help the victims . He rescues a young girl named Winnie (Savannah Paige Rae) and helps her mother, who has a dislocated leg . With assistance from Winnie, he rescues another couple involved in the accident . </P>

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