In the port city of Mariupol, where Ukrainians are trying to fend off a Russian advance, an ambulance raced into a city hospital Sunday, carrying a 6-year-old girl mortally injured in Russian shelling.

She was pale. Her brown hair was pulled back with a rubber band. Her bloody pyjama pants were decorated with cartoon unicorns. She was brought in with her wounded father, his head bloodied and bandaged.