Smell – A distinctive, strong odor similar to rotten eggs.
See – A white cloud, mist, fog, bubbles in standing water, blowing dust or vegetation that appears to be dead or dying for no reason.
Hear – Roaring, hissing or whistling.
If the odor is strong, leave immediately and take others with you.
If you are outside, leave the area immediately.
Do not light a match or smoke, turn appliances or lights on or off (including flashlights), use a telephone or start a car. Doing so can produce sparks that might cause the gas to explode.