For a little over 30 years there was a natural gas leak on our road about 500 feet from our house. When the wind was just right it would fill the house with that Mercaptan smell.
The gas company had been called by me and many neighbors numerous times and nothing was ever done and that again is over 30 years.
Only when the property where the leak had occurred was put up for sale did National Fuel Gas come out to fix it. Evidently the Realtor could not sell the land with that stink.
Small leaks which are NOT enough to explode are inconsequential to NFG as gas is so cheap (unless you have to pay for it in you heating bill).
And by the way Methane can be burned as a fuel and we are stinking rich with the stuff (no pun intended, well yes)
An important fact to keep in mind, natural gas is lighter than air, so it will slowly float up and away. A small leak, with enough openings to the sky, and it’s relatively harmless.
LP gas, on the other hand, is heavier than air, and it will seep into the low spots, basements, sewers, any low area. It collects there, and over time, minutes, hours, months, it becomes a bomb. All it takes then is an ignitions source, a flipped light switch, a dropped rock or tool that sparks and things could end in an enormous explosion.