I remember seeing an episode on how some doomsday preppers were burying prefab underground shelters on their property and stocking it with food/water/weapons/et

I remember seeing an episode on how some doomsday preppers were burying prefab underground shelters on their property and stocking it with food/water/weapons/etc. There was this guy being interviewed who smiled and said he wasn't stocking anything, but he wasn't too worried. He said he'd mapped out all the prepper locations around his property and if things went south - his sons would harden their tractors with steel plates and pull those things out of the ground to "harvest" the goodies within.