im really sorry about your loss, thats soo sad. but keep us posted! i think you should get a couple of other little chicks, or some hens.. you cant let that lovely coop go to waste now can we!! she or he (not sure about the large comb) was soo happy with you, you didnt do anything wrong. sometimes they just die.. its so sad. my friend said she had one die from being scared to death/shocked... a little boy was riding his bike and came around the corner and scared her hen, it made this weird squawking noise, and then just died...
im sorry for your loss