Two whole schools of mathematics died in "unfortunate and unfitting circumstances", namely the Lwów school and the Warsaw school: http://en.wikipedia.org/wiki/

Two whole schools of mathematics died in "unfortunate and unfitting circumstances", namely the Lwów school and the Warsaw school: http://en.wikipedia.org/wiki/Massacre_of_Lviv_professors http://en.wikipedia.org/wiki/Massacre_of_Lviv_professors http://en.wikipedia.org/wiki/German_AB-Aktion_in_Poland http://en.wikipedia.org/wiki/German_AB-Aktion_in_Poland http://en.wikipedia.org/wiki/Stanis%C5%82aw_Ruziewicz http://en.wikipedia.org/wiki/Stanis%C5%82aw_Ruziewicz http://en.wikipedia.org/wiki/W%C5%82odzimierz_Sto%C5%BCek http://en.wikipedia.org/wiki/W%C5%82odzimierz_Sto%C5%BCek http://en.wikipedia.org/wiki/Herman_Auerbach http://en.wikipedia.org/wiki/Herman_Auerbach http://en.wikipedia.org/wiki/Stefan_Kaczmarz http://en.wikipedia.org/wiki/Stefan_Kaczmarz http://en.wikipedia.org/wiki/Antoni_%C5%81omnicki http://en.wikipedia.org/wiki/Antoni_%C5%81omnicki http://en.wikipedia.org/wiki/Juliusz_Schauder http://en.wikipedia.org/wiki/Juliusz_Schauder http://en.wikipedia.org/wiki/Stanis%C5%82aw_Saks http://en.wikipedia.org/wiki/Stanis%C5%82aw_Saks http://en.wikipedia.org/wiki/Stefan_Mazurkiewicz http://en.wikipedia.org/wiki/Stefan_Mazurkiewicz http://en.wikipedia.org/wiki/Adolf_Lindenbaum http://en.wikipedia.org/wiki/Adolf_Lindenbaum http://en.wikipedia.org/wiki/Samuel_Dickstein_%28mathematician%29 http://en.wikipedia.org/wiki/Samuel_Dickstein_%28mathematici... http://en.wikipedia.org/wiki/Leon_Chwistek http://en.wikipedia.org/wiki/Leon_Chwistek http://en.wikipedia.org/wiki/J%C3%B3zef_Marcinkiewicz http://en.wikipedia.org/wiki/J%C3%B3zef_Marcinkiewicz Some members emigrated before or during the war and spread all over the world, mostly in the US. After 1945 almost none of the original members were still alive and in Poland/Ukraine.