(CNN) — Holocaust survivor Borys Romanchenko, 96, was killed in a Russian attack on the city of Kharkiv, Ukraine, on Friday. The Buchenwald concentration camp memorial institute confirmed Romanchenko’s death in a series of tweets. Romanchenko survived the Buchenwald, Peenemünde, Dora and Bergen-Belsen camps during World War II, the institute said. And he added that the entity was “surprised” by the news of his death. He also noted that Romanchenko worked “intensely on the memory of Nazi crimes and was vice president of the Buchenwald-Dora International Committee.” The discovery of Buchenwald, on April 11, 1945, began the release of more...