Lonely quail chick

I had several chicks that hatched, but 1 by 1 they've been dying off in the week since they've hatched.

Now I'm only left with one chick who seems to be doing well. I'm worried about raising a chick on its own. They are social animals and I can't just put him in with the adults. I'm worried it won't survive being alone, or if it does, it won't function socially with the others. What can I do for it?

I'm not sure why these chicks have been dying... this is my fourth time brooding and I've never lost so many. Though this is the first time I've used eggs delivered through the mail.