Yesterday AM, I gathered eggs and one had just a tad of blood on it. I thought that was strange. I've never seen one like that before. But I could not find which hen seemed injured. They all checked out fine and was normal. Then today I saw my most beautiful Silver laced Wyanotte acting kind of odd. She was just sitting by the water dish and didn't even walk away as I worked to free up some ice out of the dish. I figured she was just enjoying the heat lamp I have over the waterer, but I decided I better come back in a couple hours and check on her anyway. I pat her back and left the coop. When I came back 3 hrs later, she was dead. She had an egg most of the way out and it appeared she had bled some. What killed this hen and how can I prevent this from happening to another. I'm pretty new at keeping chickens. I've only had these for one year. Thanks for any advice.