Which character dies in a plane crash at the end of season 8?

Lexie Grey dies in a plane crash at the end of season 8 of Grey's Anatomy.

Her death occurs in “Flight,” the season eight finale, which originally aired on May 17, 2012. Lexie is trapped beneath part of the wreckage after a plane carrying several Seattle Grace Mercy West doctors crashes in the woods. Meredith, Cristina, and Mark Sloan try to help, but the debris cannot be moved safely.

Mark stays beside Lexie during her final moments and tells her about the future they had imagined together. Lexie dies at the crash site, while the other survivors—including Meredith, Cristina, Derek Shepherd, Arizona Robbins, and Mark—face serious injuries and the struggle to escape.

This event is often confused with later deaths in the show, especially Mark Sloan’s death from complications after the same crash. Lexie dies during the crash episode itself; Mark survives the initial accident but later dies in the season nine premiere. Chyler Leigh portrayed Lexie from season three through season eight.