Whups.

Video of the Falcon 9 landing,  burned down, fell over, then sank into the swamp. Or something like that. Basically it boils down to “oooh, so close.” I’m not convinced that the rocket would have stayed upright even if the landing gear hadn’t collapsed, due to the rough seas; but it’s still a hell of an effort.

Falcon lands on droneship, but the lockout collet doesn't latch on one the four legs, causing it to tip over post landing. Root cause may have been ice buildup due to condensation from heavy fog at liftoff.

A video posted by Elon Musk (@elonmusk) on Jan 17, 2016 at 7:07pm PST

Given that weather seems like it might have played a role here, my earlier comment hearkening back to the Challenger suggestion “don’t launch when it’s cold” suddenly seems pretty applicable. “Don’t launch when it’s foggy,” or, more likely, “don’t expect to get it back if you launch when it’s foggy.”