That wasn't eaten, it was laid as a soft shell egg.
A lot of times, it's just a glitch in a new layer, especially production birds. There's not really much you can do about it except see if it continues. A bird that constantly had issues like this may need to be culled, that would be your call. But usually, it's a one-off thing and you don't have ongoing issues.
What are you feeding them? If it's layer feed, you should be good. If it's grower or all flock, something like that, offer oyster shell for some supplemental calcium. New layers should have a good store already and this wouldn't be from lack of calcium, but is won't hurt either.