Playing With Fire » Blowing (Up) Bubbles
dramatic demonstration of why the same gas that heats your house can also make it explode Living in the Midwest, where heating homes with propane is common, I periodically see reports in the local paper that yet another unoccupied house has exploded. They often note that the roof was found in the basement, while the walls were spread some distance into the neighboring fields.
Roof-in-basement syndrome begins when propane, which is heavier than air, leaks and fills up the lower levels of a house, mixing with the home's ambient air. Once the layer of gas reaches the height of a pilot light in a stove, it triggers a huge explosion. (The refinery adds a very strong odor to propane, so if people are home, they typically notice the leak before the concentration approaches a dangerous level.)