Can facebook conversations delete themselves/disappear on their own?

[Hamish]

Is it possible for an entire chat history with someone to wipe itself without an human interference, like the entire chat history, nothing left?

I also use the facebook app "messenger" which has the lighting symbol in the cloud I think on my s3.

[Abhinav]

Nope. No digital data stored disappears on its own. Most probably you deleted it by mistake or moved it somewhere (like Other). If you're sure that didn't happen, check for other signs to ensure that your account was not hacked. If in doubt, change your password immediately.

[Lili]

No. I'm afraid not. You can only delete your own messages and conversations.