If a member of a group dies, all members of the group should be concerned. What constitutes a group? Not defined, and therefore we should cultivate an expansive definition of this idea in our lives, as John Donne advises in his famous poem. One who performs destructive labors on Shabbos is exempt, unless the destruction leads to something constructive. Is circumcision a wound? Rav Ashi says no, it is a repair. I note that nowhere is circumcision called striking the final blow, from which I learn the human is never finished, we should always be working on ourselves. One who traps a bird in a closet or a deer in a house on Shabbos is liable, but one who traps a sparrow in a house is exempt because the bird does not submit to capture until it is actually in hand. If one traps a snake on Shabbos to prevent it from harming people, he is not only exempt but this action is also rabbinically permitted, like locking a door which was already closed, on a deer that was trapped in a house before Shabbos began.