Why would chicks die late- could it be the heat?

[Judexxwhite]

Hi,
My hen recently hatched only 3 eggs out of 12. Sadly when I cracked the remaining 9 eggs, the chicks were really well formed and must have died just before hatching. Im wondering what happened as I have never had this before.
Some reasons I thought of are-
We have had really hot weather and maybe the eggs over heated.
We had a huge storm of thunder and lightening storm a day or so before the eggs were due.
The hen had pooped in the nest and some of the eggs had dried pooh on them- perhaps contamination?
We moved her and the eggs inside a day before hatching as the weather was really bad- maybe we disturbed the eggs somehow?

Any other ideas.

Thanks Jude

 

[sourland]

Hi, Jude, welcome to BYC. It is possible that after the move she may not have incubated the eggs adequately. Soiling the nest may also have been part of the problem.