Those who died at Katyn included soldiers (an admiral, two generals, 24 colonels, 79 lieutenant colonels, 258 majors, 654 captains, 17 naval captains, 85 privates, 3,420 non-commissioned officers, and seven chaplains), 200 pilots, government representatives and royalty (a prince, 43 officials), and civilians (three landowners, 131 refugees, 20 university professors, 300 physicians; several hundred lawyers, engineers, and teachers; and more than 100 writers and journalists). In all, the NKVD executed almost half the Polish officer corps. Altogether, during the massacre, the NKVD executed 14 Polish generals: Leon Billewicz (ret.), Bronisław Bohatyrewicz (ret.), Xawery Czernicki (admiral), Stanisław Haller (ret.), Aleksander Kowalewski (ret.), Henryk Minkiewicz (ret.), Kazimierz Orlik-Łukoski, Konstanty Plisowski (ret.), Rudolf Prich (killed in Lviv), Franciszek Sikorski (ret.), Leonard Skierski (ret.), Piotr Skuratowicz, Mieczysław Smorawiński, and Alojzy Wir-Konas (promoted posthumously). Not all of the executed were ethnic Poles, because the Second Polish Republic was a multiethnic state, and its officer corps included Belarusians, Ukrainians, and Jews. It is estimated about 8% of the Katyn massacre victims were Polish Jews. 395 prisoners were spared from the slaughter, among them Stanisław Swianiewicz and Józef Czapski. They were taken to the Yukhnov camp or Pavlishtchev Bor and then to Gryazovets. Up to 99% of the remaining prisoners were killed. People from the Kozelsk camp were executed in Katyn Forest; people from the Starobelsk camp were killed in the inner NKVD prison of Kharkiv and the bodies were buried near the village of Piatykhatky; and police officers from the Ostashkov camp were killed in the internal NKVD prison of Kalinin (Tver) and buried in Mednoye. All three burial sites had already been secret cemeteries of the victims of the Great Purge of 1937–1938. Later, recreational areas of NKVD/KGB were established there.