At the point where a couple of nasty things have been set off, anything which will make a loud noise will elicit a response. The danger of that is that a noisemaker might just be bait to draw experts (or 'looky-loos') into the kill radius of something really nasty. Anything that makes a big noise, lethal or not, could be used to draw police resources to a different part (or parts) of town, taking the heat off of criminal activity elsewhere.