Nelson Mandela turns 93

Over 12 million people sang "Happy Birthday" to Nelson Mandela today, challenging a world record. The former South African president and human rights icon turns 93 today. His foundation has urged people to mark the second annual "Mandela Day" by devoting 67 minutes of volunteer work today, representing the 67 years he devoted to South Africa's political struggle. Nomsa Maseko  of the BBC reports from Johannesburg.