That was an unusual setup (at least I hope it's unusual) where the gas piping under the street runs at working pressure (for the furnaces) with no local regulat

That was an unusual setup (at least I hope it's unusual) where the gas piping under the street runs at working pressure (for the furnaces) with no local regulators at the houses. So a central fault (accidental cross connection to high pressure) caused a catastrophe. Where I live, and hopefully most places, the distribution network runs at high pressure - causing a nice loud hiss when someone backhoes into it, which surprisingly never seems to cause a fire - but with each house individually regulated. One hopes that the house regulators have a "fail closed" mode on input overpressure, but I don't actually know.