Why are some of my chicks dying in the middle of hatching?

[FarmFam6]

So I took eggs from under my broody hens and they were laying them at different days, then i got an incubator and i had to take them and put them in the incubator. They started hatching a week ago and so far i have 8, but 3 of them were a surprise and had, from what i saw gotten pretty far but died in the middle of hatching. There heads were there and they looked fine from the outside but when i opened them they were all different, one looked like it was bloated and was yellow on the inside and i saw the veins like it was about to pop, the other looked like the yoke was shriveled and was a bit bloody, and the other looked like it had pushed its guts out. Im new at this and i have a feeling it has something to do with the alive and hatched chicks pushing them around and/or the fact that they were hatched in different dates but i wanted some help from professionals. Please help, i hate seeing those chicks dead.

 

[sumi]

I'm sorry to hear you had such a disappointing hatch. Here is a day-by-day breakdown of possible causes for embryo mortality:

https://www.backyardchickens.com/a/egg-failure-to-hatch-diagnosing-incubation-problems

Hope that helps!