Grey's Anatomy, Season 6Edit
Mary and her husband Bill were present in the hospital on the day of the Seattle Grace Mercy West Shooting but Bill left to get Mary some food. During the traumatic event Mary was placed in the same life and death situation as the doctors and had to help her surgeon Miranda Bailey in saving the life of Charles Percy who was shot. They weren't sucsessful and a devestated and traumatized Mary is reunited with her husband after the shooting.
Grey's Anatomy, Season 7Edit
Six months later, Mary returns to the hospital where Bailey is relieved to see her and they prepare for her simple and straightforward procedure. Afterwards, however, a rare occurance results in Mary being unable to wake from the anestesia and she fell into a coma. She died a month later, at a great personal loss to Bailey.