> Whenever natural gas supply is turned off in the US, for any reason, only the gas company can turn it back on

Doesn't match my experience. My colleagues and I are able to turn on or off the gas supply to our houses at will.

often around here in texas, when the gas is turned off due to an issue, the gas company disables the meter, or even removes or bypasses it. And I live in gas land, where we have natural gas piped in to the kitchen, bathrooms, laundry, outside for grills, as well as the furnace. We've seen it a lot, if you call the gas company about smelling gas, they come and remove your gas meter until you hire a plumber to go find the leak.