I had the most grusome experience to date!!! Unfortunatly i put two small chicks in a coop with 2 older hens and 5 pullets, when i checked in the morning they had pecked one of the chicks to death!!!! they had basically skinned the little creature, I was discusted with them that it took days...
sorry about the loss of ur hen how is the other hen coping?
With regard to hens killing chicks: I introduced two baby chicks to two adult hens and being new to raising hens I left them alone with the hens when I returned about 20mins later one of the chicks had hardly any feathers left on her...