MUNICH, Germany — Wolfgang Wagner, the grandson of composer Richard Wagner and the leader of the Bayreuth opera festival for more than half a century, has died. He was 90. Wagner died Sunday, the festival said in a brief statement on its website. It did not give further details. "Wolfgang Wagner dedicated his whole life to the legacy of his grandfather," the festival said -- adding that his long service as the event's leader means that he "goes into history as the longest-serving director in the world."