Book about no one speaking up when they should have.

I’m getting more intrigued by the idea of some events throughout humanity’s history that were tragedies or atrocities that one would have expected people to speak up and try to prevent…e.g. Waco, Challenger Shuttle Launch. Or maybe people did speak up but it went ahead anyway.

I’m interested in any non-fiction books describing one of these types of events. If it hits on the psychology behind it even better, but not necessary.