That's interesting and love the UT site!
My concern with cinder block construction is what happened to the schools. Pretty sure they were cinder block.
True. I doubt they would have been filled with concrete though. That plan takes about 25 cu yards of concrete. If my math is correct, that's about 625 bags at about $4 a pop is about $2500 plus the rebar, plus the fill sand plus the other supplies = super duper pricey. Not to mention the effort. I would really be tempted, were I building this, to do it half sunk into the ground with a sloped embankment around it.
Then again, if I have the kind of money to build this, I'd probably have money to have land and to sink it more than a few feet in the ground where the drones would have a harder time spotting it on thermal sensors.