Episode: Season 8, Episode 24
What happens: Anything can happen on this medical drama, even catastrophic plane crashes. When the surgeons get stranded after their ride goes awry, Lexie gets severely injured and dies at the site of the wreck. It's especially heartbreaking and unfair, since she had just told Mark that she loved him days before her death. At least now, we hope Chyler Leigh is living her best life on Supergirl as the titular character's big sib!