Knowing where you gas shut off vale is before for you need it.
Liquid Propane is stored in large tanks outside your home. The are usually placed in the rear or side of the house out of view from the street. The shut off valve will be attached to the top of the tank. The valve will have a handle much like an outdoor water faucet or BBQ tank, which you can just use your hand to operate. Turn the valve clockwise to turn off the gas.
Natural Gas is brought into your home through underground piping. To locate the gas shut off valve, you simply need to find the gas meter. The meter could be located in the basement, garage, utility room or outside of your home. The shut off valve will be located next to the gas meter on the pipe feeding the meter. You will most likely need a crescent or pipe wrench to do this.
In this short video you will see how to turn off your gas.