Serious tensions arose between ethnic Czechs and Germans during both world wars . During World War II , most of the town 's ethnic German residents sided with the Nazis ; the German-run town council renamed the main square ( until then named after president T. G. Masaryk ) after Adolf Hitler . World War II brought a rise in anti-semitism and attacks on the Jews that reflected what was happening in Germany . On Kristallnacht ( 10 November 1938 ) , townspeople destroyed the synagogue . In March 1939 , city police arrested 800 Jewish men , and had some deported to the Dachau concentration camp . During 1942 – 1943 , ethnic Germans sent the remaining Jews to Theresienstadt and other German concentration camps in occupied Poland . Fewer than 300 of the town 's Jews survived the Holocaust
Kristallnacht
Kristallnacht
Olomouc