TITLE: Mathematical research interrupted by a war
QUESTION [43 upvotes]: I am not sure that this is appropriate at MO, so if not, please, delete this.
This is inspired by David Hansen's question where he asks about mathematics done during the WWII. I would like to ask the opposite question: 

what are some examples of mathematical research interrupted by a war?

Everyone is aware of the terrible damage inflicted by the war on the Polish mathematical school. The dramatic destinies of Stefan Banach (who lived in very difficult conditions during the WWII and died soon after it), Juliusz Schauder (killed by Gestapo), Józef Marcinkiewicz (killed by NKVD) and of many others have much influence on the conscience of mathematicians in Central Europe (including Russia, and I believe, not only here). 
When I was a student an idea was popular in Soviet Union that war moves science. I must confess, I am a partisan of the opposite one: war kills science. I would be grateful to people here who would share their knowledge and give illustrations. 
P.S. By war I mean any war, not necessarily WWII.

REPLY [6 votes]: Eugenio Elia Levi's death during WWI had a profound impact on Italian mathematics. Though still quite young, Levi had signalled himself as a mathematician willing to recognize the  relevance of the then emerging
Lie theory, following the work of his mentor Bianchi. When he was just 22 he published the paper in which what will thereafter be called Levi factors were introduced. 
Moved by very strong patriot feelings, despite the fact that he could have been exempted from military duties, he voluntereed and was killed by a stray bullet after Caporetto's defeat. 
Lie theory in Italy remained largely unexplored, with Luigi Bianchi being one of the few trying to convince his students of its relevance. 
A "missed opportunity" for the Italian mathematics.