When I was about 12, we had some lowlifes who lived down the road from us. They had a foster daughter my age, and we were vaguely aware that she was not being treated well. Well, one night the foster mom physically attacked her, hitting her, tearing at her clothes, and scratching her face. "Megan" ran away from the house (in the rain, in winter) and ran to our house because she couldn't think of anything else to do. Imagine me coming home from swim team practice, to the shocking sight of my mom and a girl I knew, sitting in our living room crying and holding a towel to her face.
There weren't really procedures in place for child-abuse emergencies in that time and place, but my mother called a friend who worked for DFACS. She called someone who came and got Megan, and got her to a new foster home that night.
The new foster home was very kind to her. She appeared at school a few days later in nice new clothes and with a smile on her face. They adopted her eventually. She's one of my Facebook friends now and has a family of her own.