Barred Rock chick is weak and not chirping

[HoneyBeeHomestead]

I have 5 other chicks in the same area as the ones that passed, not together with them and they are absolutely normal today.

All of my chicks are in the same area, they all looked fine except for the one that died last night, but all the other ones acted normal, today when I went out there was another one sick

 

[HoneyBeeHomestead]

The Brahma just passed, I noticed that she had mucus coming out of her mouth. I am worried about loosing more chicks, does anyone know what this is?

 

[Mybackyardpeepers]

All of my chicks are in the same area, they all looked fine except for the one that died last night, but all the other ones acted normal, today when I went out there was another one sick

It might be something contagious I hate to say. I was worried about my other chicks being in the same area, because of airborne illnesses.