This applies mostly in cases of gas appliance fires for which you could turn off the gas supply at the appliance shut-off valve or at the meter valve. If you have a gas leak, such as from a broken gas line, then turning off the valve would not necessarily shut it off.
Even if there is a gas leak and it is not burning, you still need to get out of the building and notify the proper authorities. Any spark could cause the gas leak to turn into an explosion.
If the gas fire is burning out of control or spreading and there is immediate danger of the building lighting on fire, then just call 911 (or your local emergency number). If it is a small, controlled fire and there isn’t immediate danger of anything else lighting on fire, then you can contact the utility company first to come and shut off the gas.
This is advisable even if the utility company was able to turn off the gas supply and put out the fire. The fire department is more experienced in assessing fire risks, so they will be able to examine the property and surroundings to make sure that the issue will not repeat itself. In the case of gas leaks, it’s especially important for the fire department to inspect the premises and surrounding buildings for gas that has migrated and to make sure that the burning gas is the only risk.
If it isn’t safe to turn off the burner dials for your grill, then you can also shut off the gas supply at the propane tank by twisting the valve all the way to the right to close it.
Never dump water on a grease fire to try to put it out. The water can just spread the fire and make it worse.
If you don’t have baking soda, salt can also work to smother the fire. Don’t use flour or sugar to try and smother the flames because they are both flammable.
Keeping your gas grill clean by scrubbing it thoroughly with a brush after each use will prevent most serious grease fires in the future.