what could have happened?? Dead hen with bloody vent area!

[Bec]

A very good friend of mine lost of of her hens today

She went out and found her dead in the nest box. When they turned her over, her vent was bloody!!

Any ideas what could have happened?

 

[chkn]

Maybe she had a bad prolapse or an egg broke in there, cocci would give blood in poop, but it must have been something reproductive since she was in the nesting box? It's a tough one, it must have been pretty sudden whatever it was.