I wonder how much of that was by design, if any.

An old friend used to work in a chemical factory in, must have been Minnesota in the 60s or 70s.

She would talk about how they had a row of sheds with three walls for mixing certain dangerous chemicals. Each shed had an open or really thin wall facing the river.

If one went up, well, that person was probably gone, but at least it wouldn't start a chain reaction. It would explode in exactly one direction -- away from the plant, away from all the other dangerous chemical sheds.