René Burri, a photographer with Magnum Photos, has died after a long illness. He was 81. A statement from his family says:"With René Burri the world of photography loses one of its most powerful artists, a true humanist, who skillfully documented from behind the scenes the suffering and joy of human kind."The Swiss photographer, born in Zurich in 1933, began work with the venerable photo agency in 1955 and became a full member in 1959.