Tributes flood in for S. African anti-apartheid icon Kathrada Celebrated South African anti-apartheid activist Ahmed Kathrada, a Robben Island prisoner and one of Nelson Mandela's closest colleagues in the struggle against white rule, has died aged 87. "I can imagine how pained he was that he left at this particular time. All what he had fought for was not what is going on today", said Winnie Madikizela-Mandela, Nelson Mandela's ex-wife and anti-apartheid activist. SOUNDBITES