Violent deaths should never happen. But when we are witnesses to such evil, we must engage even more fully with the work of perfecting the world.
Holiness is meant to pervade all of daily behavior, not to inhabit the high points of experience only. Love means reaching out toward neighbors and the world with the same care, regard and generosity we normally reserve for ourselves and those closest to us.
God tells Moses to tell Aaron not to come before the Holy of Holies regularly -- so that he will not die like his sons Nadab and Abihu -- because the Divine Presence appears there as a pillar of cloud always.