Locate the main gas shutoff valve.
Your main gas shutoff valve is normally located near your gas meter. The most common places are on the side or front of a building, a cabinet located inside a building or a cabinet meter outside a building.
Have a wrench handy.
Keep a 12- to 15-inch adjustable pipe or crescent-type wrench or other suitable tool near your main shutoff valve so you don’t have to search for one in times of emergency.
Give the valve a quarter turn.
The valve is closed when the tang (the part of the valve you put the wrench on) is crosswise (perpendicular) to the pipe.