the eggs looked exactly the same yesterday. is there a problem with the top one or is it just about to hatch. had them in the incubator for around 2 months.
i looked closely and i can see the baby's head. i didn't think it would be ready to hatch yet because last time i candled it i couldn't see much inside. i'm a bit nervous and worried that the baby won't be able to hatch. how long does it take a collapsed egg to hatch? should i cut the shell if it doesn't hatch by tonight?
I don't see your pictures so am answering off the cuff so to speak. My first thought would be that the shell could have been too thick for her to break out. My second guess would be that the egg could have been turned over somehow. Perhaps by another hatchling? Did you mark them to know which side was top? I've heard flipping them may drown the baby in later development. Lastly I would check to make sure there was no dip below 76 in temperature - I'm not sure how cold or for how long it would take to kill an egg but checking would be a good idea.
It also could just be "one of those things" where the gecko was developed incorrectly and just couldn't hatch or make it. It may not be obvious, it could have been something with her heart or other internal organs being unable to support her body as it got bigger. It happens every now and again with all animals.
i'd rather suspect something wrong with it's internal organ development. the humidity is good, i check the temperature very often, which is at a constant of 80.6, there were 2 eggs in the cup and the other didn't hatch yet. the vet told me that it may have died because the female has hypocalcemia, which made the egg's shell too difficult to break, but i dust the insects with calcium carbonate and zoo med reptivite almost every time i feed the geckos. she said that calcium carbonate is not that good for the geckos and said that i should give them liquid calcium from now on.