If you smell natural gas or suspect a gas leak you should follow these safety measures.
Look:
For a damaged connection to a natural gas appliance.
If you see debris, water or dirt being blown in the area it could be caused by a leak in the pipe underground which can be just inches below the surface.
Dead or dying vegetation in the area over or near the gas pipeline areas.
Fire or explosion near the gas pipeline.
Exposed pipeline after an earthquake fire, flood or other disaster.
Listen:
An unusual sound, such as a hissing, whistling or roaring sound near a gas line or appliance.
Smell:
The distinctive odor of natural gas.
If you smell natural gas or suspect a gas leak
Call 911 promptly after evacuating the area if the damage results in a threat to bodily harm or property damage.
Do Not smoke or light a match, candle or other flame.
Do Not turn electrical devices or light switches on or off or use any device that could cause a spark.
Do Not start an engine or use any device including a telephone which could cause a spark.
Do Not attempt to control the leak or repair the damaged pipe or meter. Natural gas leaking from a plastic pipe can create static electricity that can ignite the natural gas.
Do Not use or turn off any equipment that could cause a spark. Motorized or electrically powered equipment or vehicles may create an ignition source if natural gas is present. Safely abandon any motorized or powered equipment or vehicles.
This information is provided by So Cal Gas Company