It may be hard to say what actually happened. Please give me some expert theories of what may have happened.
I had a mallard sitting on her 10+ eggs in my yard. I have been watching her carefully from my window for past 3-4 weeks since I first noticed her (she may have been there longer). There was a bad storm and tornado warning last night pre-dusk. I did see mommy carefully returning from the lake to her nest moments before the storm. This morning I saw mommy was gone, and eggs were all open, one actually smashed and many with patches of blood inside them. What may have happened? Could the hatchlings may have left on foot or someone ate them?
Here are the photos