LPG, (liquid petroleum gas) is obviously stored under pressure and that is why it’s in a liquid form. When heated up (this can be by direct sunlight), it has an expansion ratio of 270-1 meaning its current pressure can increase by 270 fold. So any weak or improperly maintained cylinders could fail. I’ve seen a small aerosol deodorant can, which was left on top of an oven take out the gable end of a house. I’ve also seen a medical oxygen cylinder completely destroy 4 houses in a row of terraces. All cylinders under pressure have the ability to be extremely dangerous. Just type in BLEVE (boiling liquid expanding vapour explosion), into Google or YouTube to see the devastating effects that it can have.