I love this idea. I often think of designs for bunkers and underground shelters. If funding permitted, I would already have one or at least have one in the works. I would buy a large plot of land, (preferably with enough open space to potentially farm). Then construct a bunker with excessive security measures. Ample storage space. And ofcourse, an emergency exit tunnel, with the exit being both hidden and far from the main entrance to the facility. If I knew any one who was rich, and owned a large parcel of land, I would assist them in building such a structure and stocking it. And when the dead came, I would defend it with them to the death.