Mary is a woman who was injured when a party bus she was on crashed.
Susan, Mary, and Carla rented a party bus with their friends for a Mom's Day Out. Their driver was overtired and drove the wrong way up an off-ramp and crashed. The women were all ejected from the bus. Mary had an injury to her leg, while Susan was impaled on a piece of the bus and Carla was trapped under the bus. The driver was dead on arrival. Station 19, on their way to the hospital with another patient, stopped to help. They cut the bar that was impaling Susan and then lifted the bus off Carla to free her. They set up a nearby triage, where they treated Mary and the other six women. Mary had an open fracture to her leg and they struggled, but eventually stopped the bleeding. Once Carla was pulled out from under the bus, she crashed, but they were able to resuscitate her. All the women were then taken to the hospital.
Mary chose the bus because it was supposed to be safer.