It appears that one of the three eggs in the Decorah bald eagle nest near the Fish Hatchery has failed to hatch.
It's uncertain whether this was the first egg or the third egg laid by the bald eagle couple, but either way the egg has passed the time in which it should have hatched.
Raptor Resource Project says bald eagle eggs fail to hatch anywhere from 5 percent to 25 percent of the time.
The organization's Facebook page says eggs fail to hatch because they are either infertile or nonviable. Infertile eggs occur when the timing of the sperm and ovum do not match. Nonviable eggs occurs when an embryo fails to develop properly and dies, most commonly because of insufficient incubation, which means that eggs are not kept at the proper temperature and humidity and turned regularly.
A discussion of eagle egg hatching can be found at http://raptorresource.blogspot.com/2016/04/is-last-egg-going-to-hatch.html. In the meantime, eaglets D24 and D25 continue to entertain with their antics, which can be found at http://www.raptorresource.org/