Children sing as U.S. first lady Michelle Obama, unseen, visits the Hector Pieterson Memorial in Soweto, South Africa Wednesday June 22, 2011. Pieterson, age 13, was one the first students to be killed during the 1976 Student Uprising in Soweto. He has since become a symbol of youth resistance to apartheid. This uprising started on 16 June as a peaceful protest march organized by school students in Soweto. (AP Photo/Themba Hadebe)