Wow, Pete's really changed over the years. I can't see him trying to keep the other players alive like this when he played as R2-D2. I can definitely see the sand suddenly getting a sinkhole like this too with the previous rumors of something lurking down here though, so geological causes need not even factor into it here.

Ok, it looks less likely now that Poe made it out of the fighter, but we haven't had this scene pay off yet, so I'm still pretty sure he's fine. Somehow. If it was a tabletop game, I'd say "whelp, that's just the result of bad decisions", but the movie wouldn't spend the time on the scene in order to just throw it away so soon. Then again, with how Lor San turned out, I feel a bit like Corey here.

So now all Finn's got on hand is a burnt jacket, the white armor, and whatever's still in the belt. And the plume of smoke is probably gone now too. Realistic odds of survival on the planet? Very low before and they somehow found a way to go even lower.