I don't know that anyone will be able to tell you for sure what happened because there are so many factors involved. My own green egg did not seem to impact the others from what I can tell, but they haven't hatched yet so I don't know if they'll be viable.

I did recently read a post on another forum where they (I think it was Rich Macias) suggested that temperatures may rise within egg boxes as the eggs start generating their own heat, and that it could be the reason why people lose snakes so close to hatching.

Aside from that, and this is just me spitballing here for you to consider/research on your own, they could have been exposed to a mold, bacteria, or chemical that overwhelmed them when they hatched - maybe the effort of hatching made them especially vulnerable to it. Or maybe something went wrong while they were developing internally and it only became an issue once they hatched - like underdeveloped lungs or something.

So sorry to hear about your clutch going bad! I hope the others are unaffected. Hopefully someone else with more experience can offer some insight.