Locate the main gas shutoff valve near the gas meter
Turn the valve handle a quarter turn so it is perpendicular to the pipe
If the valve is a lever, turn it until it is across the pipe
Use a wrench only if the valve is designed for tool use
Do not turn the gas back on yourself
If you smell gas, leave the area immediately and call the gas utility or emergency services from outside
If you are unsure which valve is the main shutoff, contact your gas utility or a licensed plumber