Sims keep dying for no reason?

Just to be clear, I have aging off for both my played households AND all other Sims. The townies are dying off at a ridiculously rapid rate. As in I'll go into "manage households", and the only surviving member will be an infant, or maybe a pet. This is happening to established households, like the Bjergsens, the Goths, and the Landgraabs. Nothing in my gameplay or settings that would cause this, at least that I'm aware of.

Is this related to the latest pack? Have you had this happen yourself? Or am I overlooking a setting  I didnt know about?