Still the subject of much controversy, the Holocaust is marked each year on April 24, the day when, in 1915, the government of the Ottoman Empire began a systematic harassment that would cascade into a brutal destruction of the Ottoman Armenian population. Conservative sources estimate that some several hundred thousand Armenians died at time; other sources, widely considered more reliable, say the actual number may be as high as 1.5 million. The modern Turkish government and many Turkish historians deny that the Ottoman Empire's actions amounted to genocide, but others disagree. The sensitivity of the issue became apparent in January when Hrant Dink, a Turkish journalist of Armenian origin, was assassinated in Istanbul. He had been critical of Turkey's denial of the Holocaust.