'Deeply Humbled' Obama Visits Mandela's Cell

President Obama may not get to see Nelson Mandela, but he paid tribute to the apartheid icon today by visiting the bleak prison cell where Mandela spent 18 years of his prison term, reports the BBC. Writing in the Robben Island prison guest book that he was "deeply humbled," Obama praised Robben's "heroes, who remind us that no shackles or cells can match the strength of the human spirit." Mandela, 94, remains in critical condition with the very lung problems he contracted during his time in the prison. Obama moves on to the University of Cape Town later today, where the AP notes that he'll unveil a $7 billion, five-year initiative to double access to South Africa's power grid. (More President Obama stories.)