When teaching our kids fire safety and cooking, we've told them if they smell gas to get out and tell an adult.
Today 10yo was making pancakes for everyone. She didn't notice the gas hob hadn't lit. She noticed a funny smell, but didn't know it was gas (technically the smelly additive added to gas!). Fortunately an adult did notice, and no harm was done.
So... teach your children what gas smells like, not just what to do if they smell it!
I'm well prepared to be flamed here. Her elder sister did know what it smells like due to Chemistry lessons at Secondary school.