Hello! I have a mixed flock (2 RiR, 2 silver laced wyandottes, 2 black star sex links). They are all perfectly healthy birds. I've been getting 5-6 eggs a day for weeks now. They are all a year old but started laying between November -January. They have constant access to food and water. Yesterday I was doing a lot of work outside, I'm in New England and we had our first hot day of the spring (75 degrees). The chickens were free ranging in their fenced in area and I gave them a few treats throughout the day, mostly a few handfuls of sunflower seeds. I checked eggs around 10am and saw a RIR and a Wyandotte laying together in the nest. I came out around 10:30 to check on the girls again and the Wyandotte (I think the same one, but not positive as they're very hard to tell apart) was still laying but seemed fine still. When I went out around 11:30 and noticed she wasn't out yet I was a little worried and checked and found her dead in the coop just outside the nest box. She was laying on her back, wing slightly stretched out, feet stretched and neck curled in against her chest. As I mentioned, aside from a possibly lengthy egg laying that morning, she was completely healthy leading up to her death, at least from what I could tell. Sorry for the lengthy post but I wanted to get as much detail as possible. Has anyone experienced this? I have heard of sudden chicken death and am suspecting that is the case. But I am nervous that it could have been something else and don't want another flock member to die. Her body showed no signs of trauma that I could tell (no blood or wounds). The other chickens seem fine today and I have been checking them often.