The second mourning dove pair also set up nesting on the fuse box, same routine,- mama dove 12 hours, papa dove 12 hours,- rotating egg, brooding, like clockwork, changing of the guard. They were there for the required incubation period and then they vanished. Nothing. No hatchlings. I have no idea what happened. It's possible that the fuse box gets too warm for successful hatching and survival. Robins have nested there, but their nests have more substantial "flooring". Maybe the sparse leaves and twigs that the doves throw together are not adequate insulation against the fuse box heat.