Fireworks Explosion in California

This is why there are regulations for the storage of fireworks. It says in the article that they were "commercial grade fireworks" which would mean 1.3G Display fireworks. Looking at the quick acceleration of the fire I would agree or it might be possible that it was cases of 1.75" consumer shells. For retail sale 1.75" shells are supposed to be packed in a package with a mortar or mortars for firing the shells. This reduces the density of the fireworks which makes a big difference in how fast the fire in an accident like this accelerates. However as usual in the USA there are lots of guys not following the rules and still selling cases of 1.75" consumer shells. It looks like to some small degree there may have been some propagation to 1.1G detonations. This can happen with 1.75" consumer shells especially if they contain Flash Powder. A guy in North Dakota was ordered to destroy a container of 1.75" consumer shells that contained flash powder. They put them in a big pile instead of spreading them out. The result was a 1.1G explosion that was heard over 20 miles away.

All around this is not good, the people responsible lost their lives, there is lots of property damage and this is just the kind of thing that causes more regulatory oversight. These are all good reasons to follow the regulations when storing fireworks.