How do I prevent murder?

I'm currently trying to kill as few people as possible in Dishonored. I learned the hard way that throwing unconscious people into the water instantly kills them, so I'm not doing that anymore. I assumed this was the only thing I couldn't do (short of shooting or stabbing them) that would kill an unconscious person.

However, while lazily hiding unconscious bodies, I threw someone down a staircase, assuming they'd be fine, but when I checked on them, they weren't snoring. What can't I do to unconscious people if I want to keep them alive? That is, what all kills them besides the obvious shooting or stabbing them?

Solution 1:

The critical area for an unconscious body is their head.

• Moving them around and having their head hit things will kill them.

• Dropping heavy things on their head also kills them (whale oil canisters can do this).

• Dropping them some distance will also kill them.

• Drowning with their head submerged will kill them.

• Rats will go after unconscious bodies and eat them.