There looks like there is alot of fluid in there...I would suspect the humidity was too high. It should be at MOST 65 until the last few day, then goes up to 70-75. Here is another thread that may help you: https://www.backyardchickens.com/forum/viewtopic.php?id=363717
I am sorry for your loss.
I bet your next hatch will go great!
I am sorry for your loss.
