I would wager to guess this probably wasn't successful, but it is really hard to be sure. Hatched eggs that were undisturbed look essentially like they were broken in half. All the shell pieces in this nest and the fact that there is no nice feather down circle where the eggs were being incubated, suggests that it was predated. Plus, it looks like there is wetness on the wood to the right where the metal mesh is, which suggests that cracked eggs might have been take out that way to the exit hole. But, this is basically conjecture and like trying to solve a puzzle without all the pieces. Of course, a squirrel could have gotten in there after the young were gone and been going through the box contents and breaking the egg shells up, but I guess we'll never be sure.

Thanks for the reply whwo. I went back to the box the next to day to clean it up. There were no unhatched eggs in there. Also, as I started cleaning it up, I found there was a ton of down in and under the top layer of wood shavings. That convinced me that it really was a good hatch. That and the fact that if it was predated, I would think there would have been a bunch of egg yolk and whites all dried up in the down and wood shavings but that wasn't the case. The stains inside the box have been there for a long time. Not sure what exactly caused them but like I said, several other birds/animals have used the box over the years. Next spring, I intend to be much more vigilant with the box. I also have to swap in more cedar shavings and get rid of most of the pine shavings. I understand that the pine saw dust is not good for baby wood ducks as it can suffocate them while they are covered in it.

Here is a photo of the house as it sits on the tree.