What caused my hen to die?

[gagirl02]

I have 4 hens and 2 roosters. One of my hens died this afternoon. She was 2 years old. Never had a problem out of her. She was a New Hampshire that laid brown eggs. I had let them out of the pen to roam the yard for the afternoon - this happens every day. I observed them and made sure they were all ok. They all seemed fine and acting normal. Later in the afternoon, we had a storm come up. My son in law was getting them back in the pen when he noticed the red hen, Henny Penny, struggling to get up. She was flapping her wings but couldn't get up. He called me outside and by the time I got there, about 30 seconds later she was dead. Her head was turned completely behind her. Two of the hens were on the far side of the pen looking at her, and the two roosters and a hen were closer but had moved away from her. When my husband came in from work, stiffness had already set in her neck which I had laid in its normal place. We checked her over and saw nothing wrong. No feathers were found at the site where she died, no blood, nothing abnormal at all. Any ideas of what could have happened to her?

 

[Ol Grey Mare]

Had she been laying regularly up to today?
Are you up to doing a necropsy?

 

[sourland]

Was there a darkening of her comb ? This could possibly indicate a heart attack.