Let's hear more about why it's dangerous to have them inside...
Propane gas is heavier than air. If there is a leak in your system, in an enclosed space, it will settle near the floor. This will build up and if it reaches an ignition source, it can cause quite a boom. Even if your tanks are stored outside, it is necessary to turn them off when not in use. The torch valves or hoses can malfunction and you could end up in the same boat... with it all leaking inside a closed space. I think the "why" to all of this is just as important when discussing the main problem. I'm sure you can all add to my feeble attemp at explaning the science behind the danger.
