What causes chicks to drown in shell?

[Hyroler]

I had 2 chicks drown in shell while hatching.They were perfectly fine when I went to sleep last night.They both had broken thru and had shell about 1/4 unzipped.When I checked this morning both were dead and shells full of liquid.They were early hatchers it was day 19.Had 2 hatch on day 18 successfully.

 

[Chicken-lovebirdchihuahua]

The humidity might have been too high through the incubation and when they piped they still couldn’t get enough air and died

 

[Hyroler]

Humidity was high around 75 %due to its been raining last few days .I'm at sea level only about 1/2 mile from Ocean .My incubators stay at about 45 % humidity without adding water.If I set small sponge it jumps to 60% which is good.I noticed it was high with sponge and wet weather but didn't think it would hurt.

 

[Hyroler]

Humidity is at 79% right now .I just removed wet sponge hopefully it will drop and stay around 60 I have 2 more chicks ready to unzip anytime

 

[Chicken-lovebirdchihuahua]

Good luck!

 

[Hyroler]

Got humidity around 60 now 2 more healthy chicks hatched about hour ago.Waiting on last 4 eggs to hatch today is day 21

 

[aart]

I had 2 chicks drown in shell while hatching.They were perfectly fine when I went to sleep last night.They both had broken thru and had shell about 1/4 unzipped.When I checked this morning both were dead and shells full of liquid.They were early hatchers it was day 19.Had 2 hatch on day 18 successfully.

How were your air cell sizes?