Final attempt to record building of an underground shelter using a 20 ft. shipping container. For those wondering why I didn’t simply pile dirt over it without pouring a concrete cap first….. These containers are mostly sheet metal. Heavy duty as it is, the roof and sides will push inwards from the weight. Eventually the metal will rust through and you’ll be buried alive. My way will insure it is still there a few hundred years from now. Problem is, you’d better keep an eye on your sump pump. If it goes bad or loses power, you’ll go in one day and find it the whole thing flooded. A surface alarm letting you know the water level is above where it should be isn’t a bad idea. Putting the sump pump on a UPS is also a good thing.