50 years ago, 16-year-old Seth Mazibuko led a massive protest in the township of Soweto, South Africa, to protest against the government's imposition of Afrikaans as the language of instruction in schools. Protesters were met by a police cordon who fired tear gas and opened fire on students, killing at least 176 people. The photograph of the body of Hector Pieterson, a 13-year-old boy who participated in the demonstration, in the arms of his brother, became a symbol of the massacre.