Poles were subjected to mass arrests, executions and deportations to Nazi concentration camps, and the local Jewish community was almost completely destroyed. The Germans carried out a massacre of 10 Poles at the local cemetery in 1939. The Germans closed down both Polish and Lithuanian schools and then looted and destroyed school libraries. Poles managed to organize secret teaching, but soon the Germans carried out mass arrests of Polish teachers, who were then imprisoned in a Gestapo jail in Suwałki. Nevertheless, secret Polish education continued until the end of the occupation. In April 1940 the Germans carried out mass arrests of 150 Poles, 10 of whom were publicly executed at the market square on April 24, 1940, and the wójt of Gmina Sejny was murdered in Prudziszki on April 26, 1940. Several Polish priests were arrested and deported to the Sachsenhausen, Soldau and Dachau concentration camps, where most of them died. Two priests survived the concentration camps and the war: one, who also held American citizenship, eventually settled in the United States, where he received medical treatment in the following years, and the other returned to Poland after surviving Nazi human experimentation in Dachau. Poles were expelled from church properties, which were then handed over to Germans as part of the "Lebensraum" policy. Works of art and vital records were robbed by the Germans from the local church and taken to Königsberg.