evening jimbob how are you today mate.
People forget that smokebombs are still a firework, and use a chemical reaction to to burn and let off the smoke. You only have to look at the Bradford City fire to see how dangerous something like that can potentially be.
For those who don't know of this, here's a link to the video http://www.youtube.com/watch?v=7krsXDKrTqI I won't embed the video as its not something everyone would want to watch as its not easy too at times