Bonnie Crasnoff

Bonnie was first seen on Grey's Anatomy as a victim of the train crash in "Into You Like A Train", in which she and another man, Tom, had a metal pole running through them. Before the accident, Bonnie and Tom had been strangers, but the trauma of the event and their proximity made them grow emotionally close throughout the span of their stay at the hospital. Despite being very poorly injured, Bonnie continued to be lighthearted and joke about her situation, though the doctors assessed her to be in worse condition than Tom, who at least regained some nerve endings in his feet. When the two were finally pulled apart for surgery, Bonnie bled out, distressing Meredith when no one would answer her cries for help and try to save Bonnie. The impact of Bonnie's death is significant for Meredith, as she reappears with Denny and the man from the bomb squad in Season 3, Episode 17 "Some Kind Of Miracle" when Meredith is floating between death and life. She tells Meredith that the doctors should have done more to save her, and frequently bleeds from her wound from the pole.

Bonnie's character and her story have an important psychological role in Meredith's life and her relationship with Derek. When Bonnie's heart crashed, Meredith yelled to the other doctors (including Derek Shepherd) "you can't just leave her there", referring not only to Bonnie's situation but also to her personal situation, feeling abandoned by Derek. Bonnie appears in the limbo-like scene when Meredith is dead in Season 3 to remind her to fight for her own life--Meredith was the only one who fought for Bonnie's life, and it wasn't enough. Meredith is indifferent to dying, while Bonnie hardly had a choice. Her presence in the scene, however, gives Meredith some existential thoughts.