I cracked open one of the eggs! Help!

[Ks1063]

My Buff Orpington has been sitting for 24 days. About 2 weeks in, she got off the nest to eat. There was some yolk on a few of the eggs, but I didn't find any shells broken. The eggs smelled bad, so I thought it was because of the exposed yolk. Yesterday, day 23, I broke one of the eggs only to find a fully developed chick with a little yolk attached! It was not moving, and I haven't heard anything from any of the eggs. I looked up pics of development. I would guess this chick was on day 18 or 19. I've candled the eggs, and most are solid black inside. My question is was this chick already dead, or did I kill it? I feel terrible. If it was alive when I cracked it, would there have been movement?

 

[sourland]

If it was alive when you cracked the egg, you would have seen movement - you did not kill it.

 

[Ks1063]

Why would it die? How do I know if the others are dead?

 

[sourland]

If you are on day 24, it is highly unlikely that any of the eggs are viable unless some were added to the clutch during the brooding period. My guess is that bacterial infection caused by the broken egg contaminated your nest site and eggs.