Looking for information of Jurgis Bardzilauskas (1901) and Petras Bardzilauskas (1904)

Hello
I don't know where to find the death information of Jurgis and Petras; they were brothers born in Navasiolkai (Punia parish). I seem to have found Jurgis's wife and children, and it is shown that some of them died young (1920s). I am also looking for deceased/living descendants, but I don't think that should be discussed here (the living). I'd appreciate all the information and advice given!
-Julius