Chicken looks troubled

[Cerobric]

I have one chicken that one day, started to sit in the nesting box. She sat on my decoy eggs, so I just thought she was broody, since every time I removed her from the nest, she went right back in. I proceeded to block her nest up, but she still went and sat on the wooden plate I used as a blocker.
In the evening, when the other chickens where up on the roost, then she was on the floor just standing around. I put her up on the roost and she went to sleep.
Today, in the morning when I went to open up the coop, every other chicken rushed out, but she just sat on the floor.
Usually my chickens don't like it when I pet them and run away, but eversince this one chicken started having this odd problem, she is totally fine with me petting her, like she has no energy to run.
In addition, her stool is liqud.

 

[Cerobric]

UPDATE: Shortly after writing this, I went out to check on the chicken and she was dead. It was most likely egg-bound, because there was a mixture of an egg-like substance and blood around her cloaca.
The other chickens were gathered around her and some were pecking around her cloaca and their beaks were a bit bloody.
Will the other chickens get any sort of diseases or infections from pecking around a dead chickens cloaca?

 

[chrissynemetz]

I'm sorry you lost your hen