The Society for Threatened Peoples estimates the Romani deaths at 277,100. Martin Gilbert estimates that a total of more than 220,000 of the 700,000 Romani in Europe were killed, including 15,000 (mainly from the Soviet Union) in Mauthausen in January–May 1945. The United States Holocaust Memorial Museum cites scholars who estimate the number of Sinti and Roma killed as between 220,000 and 500,000. Sybil Milton, a historian at the U.S. Holocaust Memorial Research Institute, estimated the number of lives lost as "something between a half-million and a million-and-a-half".