Why did my chicks die in the shell?

[egg-inator]

On the subject of hatching, what could make a chick zip 90% of the way and then die?

 

[ChickenCanoe]

Again, it could be a dozen things. You undoubtedly will have lots of similar questions as you continue to incubate so here is a great asset for breakout analysis.
Hope this helps.
https://ufdc.ufl.edu/IR00004437/00001

 

[egg-inator]

Thanks!