Vilna ghettos established
The Nazis establish two ghettos in Vilna. Ghetto 1 inmates perform forced labor for the Nazis; Ghetto 2 prisoners--mostly women and children--are later massacred by Einsatzgruppen and Lithuanian collaborators.
First killings by gas at Auschwitz
The SS experiments with gas as a means of mass killing, testing the use of the pesticide Zyklon B in gas form on Soviet prisoners and non-Jewish Poles.
Kovno ghetto sealed
The Kovno ghetto is enclosed, with nearly 30,000 Jews imprisoned there cut off from the outside world.
Bialystock ghetto established
Approximately 50,000 Jews are imprisoned in the Bialystok ghetto.
Riga ghetto established
Nearly 27,000 Jews are concentrated in the Riga ghetto, where they endure destitute conditions.