When the train hit six-year-old Madina Hussiny, her family stumbled to the watching Croatian border police begging for help, her body limp in their arms. The same officers had ordered the exhausted Afghan family down railway tracks towards Serbia in the dark without warning them there might still be trains running, said Madina’s mother, Muslima Hussiny. But desperate and terrified, they had nowhere else to turn. Madina was a casualty of a slow-burning crisis along Europe’s borders that aid groups and activists say is causing untold suffering.