@sag:
I was re-reading the chapter, and I've found something that has been bugging me. Or to be more precise, has drawn in my attention; however what I'm going to say might be a mere speculation.
Please check the bottom right pannel of this page here http://www.mangareader.net/one-piece/660/4. Ok at the beginning I was like yep thats just a latch or a lock or something to keep the door close and safe; but what if its not?. That was a freezer so it might be probable that instead of a lock that was a thermostat or a temperature regulator that keeps the corpse in their frozen state; it went "beep"; granted, beep is the noise of any electric appliance that goes KABOOM; but what chances are there of that thing really being something else from a mere lock?
Ohh sorry I just happened to destroy that whatshouldyoucallit that keeps your "corpses" well… dead. BTW no one has stated that they're corpses; Nami, Chopper and the kids believed they were dead by their "circumstances"; which is an educated guess but who knows we might have another wild party x joins the fray in the middle of the arc. Granted, I know im standing on thin ice here but hey I'm trying to not rule out the possibilities.
I was thinking somehing like this too. That maybe the frozen people arent dead just preserved. Maybe they have some knid of illness and they are using the kids to find a cure? Or the kids have the same sickness so if they can cure the kids they can revive the frozen people and cure them.
Or maybe thats just the freezer where they put all their failed experiments. Who knows.