LPT: Your home could experience a natural gas leak even if your house isn't hooked up for natural gas

We had been smelling a vague natural gas smell in our driveway for a few days but I didn't think anything of it because our house is fully electric. But last night I called the gas company and they had someone out to our house without 15 minutes, and turns out there was an old disused gas line under our driveway that was leaking. They're going to cut it off at the street and cap it so we won't have to worry about it in the future, but I'm totally horrified thinking about what could have happened if I hadn't called the gas company!