Dear All, BE VERY CAREFUL!!!
Natural Gas when it escapes, goes up, which is why when their is a gas leak in say the basement of a house, you get whole house confligrations so quickly. Propane, i.e. tank gas, goes down, pooling in depressions and places lower than the gas line from which it emanated. That is why when there is a leak in say a trailer or RV, the explosion comes from underneath.
Propane will dissapate in low lying places more slowly in cold weather.
Your gas company is right – turn the gas supply OFF, and fix the problem before turning it on again..