If you ever used coal gas, it had a smell similar to moth balls. Natural gas has no odour, so an additive (mercaptans) is used so a leak can be detected. I visited New Zealand in the 1980s, and Christchurch, Invercargill and Dunedin were still generating coal gas. When you light the burner on a stove, coal gas ignites with a sharp POP, compared to natural gas. Otherwise, cooking is the same either way. I toured the Dunedin gas works twice before it closed as New Zealand's last gas works in 1987. It is now a museum, one of only three such in the world. You can read about it here.

Whatever the name, if you read a reference in a novel to sticking one's head into the oven to commit suicide, this is what is referred to, not today's natural gas. Natural gas is mostly methane. Coal-derived gas includes a substantial amount of carbon monoxide. It was the dominant household cooking (and sometimes lighting) fuel until the 1940s-1950s in the US, and somewhat later in Britain.

The pipes conveying steam from the mixer have sprung a nice leak right next to the workers. Nothing like a little live steam to liven things up!

however I don't remember this level of the game?