A crowd gathers to watch Marine One, carrying U.S. President Barack Obama, land for a visit at the Demond Tutu HIV Foundation Youth Center on Sunday, June 30, 2013, in Cape Town, South

 

              A crowd gathers to watch Marine One, carrying U.S. President Barack Obama, land for a visit at the Demond Tutu HIV Foundation Youth Center on Sunday, June 30, 2013, in Cape Town, South
A crowd gathers to watch Marine One, carrying U.S. President Barack Obama, land for a visit at the Demond Tutu HIV Foundation Youth Center on Sunday, June 30, 2013, in Cape Town, South Africa. The visit comes at a poignant time, with former South African president and anti-apartheid hero Nelson Mandela ailing in a Johannesburg hospital. (AP Photo/Evan Vucci)