I have four Bluebird boxes on my property. I checked one last week and there were four eggs in it. I walked by it the next afternoon and saw all four eggs laying on the ground. Each one had a single hole in it but was still full. I think a rival Bluebird may have done it. No Bluebirds have returned to that box since.
Well everybody knows about the bird!
https://m.youtube.com/watch?v=9Gc4QTqslN4