HELP!!

[kychick15]

I don't know what's going on with my flock!! I lost a chicken Tuesday night/Wednesday morning and I thought maybe she got to wet during the storm and maybe got cold and died but then I went out this morning to let them out and I have another one sitting in the nesting box with her face in the corner and she's breathing heavy and won't move. What could be wrong?! And what can I do to make sure my last 3 don't die??

 

[Wyorp Rock]

Do you have any photos?
How old are they?
What does their poo look like?
What type of food/treats do you use?
Any signs of sneezing, coughing, runny nose/eyes?