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Rihanna wrote this on her Twitter page about Nelson Mandela after hearing about his death on Dec. 5, 2013, 'One of the greatest men who's ever lived!!! #Legend We will never forget the things this man has taught us, and we will never truly comprehend the level of strength that it took for him to endure many of his years!! Thank you #Mandela.'
(Pictured: Rihanna appears at the 2013 American Music Awards on Nov. 24, 2013.)
(ABC Photo/ Matt Brown)