lawns. it's not spectators at public shows. surprising to see. >> there are laws to how close things are to be set off. >> even with that a randomness. these are bombs going off, they happen to be beautiful ones. i spoke with captain mike lindbery, he says it's early on but they're trying to get to the bottom of what caused the simi valley mishap. take a listen. we haven't determined that completely yet. we need to get in there. it's a slow process. we want to make sure that we dispose of the unexploded ordnance and make that area safe to get in there and take a good, close look. >> it's interesting, hearing the description of the events, a mortar may have gone off the wrong way, you need a bomb squad to deal with unexploded ordnance. do you think people understand, for all of their beauty, how powerful the pyrotechniques, fi works are. >> there is an inherent danger because we are dealing with