[supplemental reaction to Day 100 readings]
Ezekiel 18:30 says, "Therefore, you Israelites, I will judge each of you according to your own ways, declares the Sovereign LORD. Repent! Turn away from all your offenses; then sin will not be your downfall."
Although personal responsibility is certainly found elsewhere in the Old Testament, it often with mythical characters--e.g., Adam & Eve--or with particularly significant people--e.g., Moses or David. Furthermore, Ezekiel's words seem particularly significant as the royalty are being shipped off to Babylon.
This is the subject of the entire eighteenth chapter, and earlier, the prophet tells the listerners that even Noah, Daniel and Job could have only saved themselves, not their family. Context.