Heh died out of nowhere

[Chicken George]

Today I went to check on my hens and I found a white leghorn lying in the coop dead. I checked to see if there were any external injuries but the only thing wrong was that her vent was "open". I didn't notice anything wrong with her at all. Anybody know what happened?

 

[iheartnh]

I'm new to chickens, so I don't have a clue - but I am sorry for your loss. Curious to see if anyone has an opinion on the cause of death.