My ducks wing feathers have been bleeding?

I own two young ducklings who's wing feathers have just started growing, and I've noticed a problem. On Saturday, one of the ducks new wing feather "sprout" had snapped, therefore bleeding and making a horrible mess. Then it happened on Sunday, but on the other wing. At that point I didn't ask about, because I wasn't too worried. So, in the night, I put them in a small crate that we had. (the one they use for transporting meat chickens in) So they spent the night in the crate and the wings didn't start bleeding. I thought it was ok, so I didn't do it on Monday night. Today, I found the duckling all bloody with both of the wings bleeding. A bit like pattern. What could have caused it? How can I stop it? Will she survive?