Battle Angel Alita: Mars Chronicle

Martian war orphan Yoko was placed in an orphanage in the frontier town of Mamiana with another war orphan, Erika. Yoko and Erika were baptised by the senior Ninon, who said she was of noble blood, but they adjusted to life at the orphanage. However, their days of repose were short-lived. A mysterious cyborg appears in pursuit of Yoko, and the orphanage is attacked. Yoko hides in a water pumping station with Erika, Ninon and the others.