“hazal said that the Torah protects and bittul Torah can bring on tzaros. We can not always know why things happen, but Chazal and later Gedolim would sometimes tie certain tzaros to certain aveiros.”
A famous example of this is the Tosfos Yom Tov, who tied Tach V’Tat in with talking during Davening. I have heard a similar idea with the Holocaust, and how the Sephardim were (mostly) saved B’Zechus that they did not talk during davening.