Some years back, a wild mallard hen nested under the boxwood shrub at the base of my front porch. Unfortunately, at some point in the night around day 14 of incubation, something got her and killed her, probably the dumb neighbor's stupid cat that was let out at night. All 8 of her eggs were still in the nest in the morning when I found her and, thanks to mild weather overnight, not too cold.
Two of them were cracked completely around in the middle apparently during the struggle but weren't leaking any contents.
I scooped them all up and put them all into my incubator. I used scotch tape to tape the two cracked ones.
All eight hatched 14 days later. I raised 8 healthy wild mallards and released them into the wild at a local park with large duck populations around 10/12 weeks of age, when fully grown and able to fly.