It is possible if it was a raccoon that the mom was eaten if she was in the box when it came by. That would be my guess if the female is missing now and the nest was a mess. Not positive but that is what it sounds like to me.
Hopefully your male finds a new female and can start over. Put up a stovepipe baffle so this won’t happen again. “If” it was a raccoon, it will not forget where it got a meal and might be back. As far as the nest I would wait a bit yet and see what happens.
Good luck.
Donna in WI