Right now from the look of those plants I would give them 100% humidity until they recover.
No they are not prone to mold at all as long as they are given proper light levels. Just put another Tupperware on top of them or a layer of saran wrap if the Tupperware is taller than the tops of plants.
It's something we hear all the time around here, and it's always attributable to the same place. Good luck with those poor little things! But if they don't make it, there are folks around the area that can help you replace them for a second shot at them.