It makes me wonder about the storage of fireworks. I mean they are normally kept in large METAL sealed containers. This is fine for helping to keep fire away from the contents, but totally the wrong thing once fire gets in or starts spontaneously.
It then becomes a very large strongly contained metal explosive device. (Big Bang and lots of pieces of metal flying about.
Makes me wonder if holes in the ground and/or built up at the sides with not so strong storage containers would be better. This way, the container wouldn't contain the forces so well and so thereby be less of an explosive force and all the force would be directed upwards and away from surrounding areas. The fallout also wouldn't be made out of large pieces of metal.
(Just my thoughts on a Sunday morning...)