There are three critical things that you must not do when you respond to an outdoor gas leak:

1. Do NOT operate any shutoff valves other than those on gas service meters and appliance supply lines. After the leak source has been detected, a representative from {Utility Name} or the local gas pipeline operator will turn off the gas, using a shutoff valve on the gas main or lateral. Never operate these valves. If necessary, you may close shutoff valves on the pipes coming out of the ground before service meters or shutoff valves on appliance supply lines, provided it is safe to do so. You must inform {Utility Name} of any valve you have closed and its precise location.
2. Do NOT spray water into gas lines. If the water pressure is greater than the gas pressure, you could flood the gas piping. This could knock out pilot lights and lead to a serious gas accumulation problem downstream.
3. Do not open any type of gas valve that has been closed. The local gas utility emergency representative will take care of restoring gas service once the area has been declared safe.