Meet two Tennessee families who are both preparing for an earthquake in the New Madrid Seismic Zone. David Mays believes all roads and bridges leading out of his neighborhood will be destroyed, so he's devising the ultimate Doomsday drone fleet. Meanwhile, 100 miles away, do-it-yourselfer David Nash is building a geodesic dome -- considered one of the most stable structures on earth as it eliminates the need for load-bearing walls -- that will house his family during the earthquake's aftermath.