How do we reconcile the obligation of hishtadlut - making reasonable physical efforts for protection - with the fundamental principle that only Hashem decides who lives and who dies, who is protected and who is not?

Hashem alone determines all outcomes; our hishtadlut (effort) cannot change His will. Our obligation is effort; Hashem controls the outcome. True hishtadlut prioritizes prayer, Torah, and Yirat Shamayim over mere physical work. While physical precautions are required, their effectiveness depends on spiritual merit. Prioritizing physical effort over prayer is a mistake; ultimate protection stems from teshuva, Torah, and mitzvot, recognizing Hashem's absolute sovereignty.