I'm referring only to the specific case of regulations which cover engineering practice (as opposed to more industry-specific regulations, for instance, which I don't know enough to comment on).
In these cases, absolutely yes! The shouldness should be codified into law.
The best mechanism (regulation vs. after-the-fact culpability; specific legislation vs. using existing frameworks, etc.) is debatable.
But companies who cause public harm by not following best practices (either intentionally or due to poor trained engineers) should be held legally responsible for preventable disasters. Just like it's done in many more mature (as in older) engineering fields.
