Sudden chick death

[JDowey]

I have been brooding 5 arucana chicks, and they all seemed rather healthy and feathering well up until yesterday when one suddenly died. They're 5 nearly 6 weeks old and had no sign of disease, I put them in their outside run as it was a warm day and Im starting to get them used to outside but still only for short bursts. When I came back and looked in on them I realised one had died with no warning. I don't think it was cold (the rest were moving about normally, not huddling or cheeping excessively) but the chick also had no signs of disease

 

[Mellowmalt]

that is very strange, my intial thought are it might have found something to eat it shouldn't have or a predator scared it. Sorry to hear. Is the run completely covered?

 

[JDowey]

that is very strange, my intial thought are it might have found something to eat it shouldn't have or a predator scared it. Sorry to hear. Is the run completely covered?

Yes the run is completely covered top and all sides, the ground is also completely bare sand with no weeds that could have been poisonus and has never been sprayed with anything (were landscaping so just put down the fresh sand)