Accidents are a big risk, but don't underestimate the number of individuals and small groups that have fundamentally anti-social philosophies. I think of groups

Accidents are a big risk, but don't underestimate the number of individuals and small groups that have fundamentally anti-social philosophies. I think of groups like antinatalists, doomsday religious groups, traditional terrorist orgs. There is even a sort of post-human futurist that sees humanity's purpose being to create a great super intelligence to replace us (may be overlap with this group and antinatalists). So, I think there we be more chances for legit accidents, but also some motivated people intentionally trying to cause harm.