Well, to be fair, the entire idea is really quite stupid (in my opinion.) It's novel, to be sure, but realistically, at least in most of the US, it would just

Well, to be fair, the entire idea is really quite stupid (in my opinion.) It's novel, to be sure, but realistically, at least in most of the US, it would just be easier to use a boring drill to make the hole, and then lower a regular (or even torpedo-shaped) coffin into it.