My observations on riots, having been caught up in one unexpectedly, and later as an MP trying to suppress one, is that they are highly intense, but very local, and vary greatly in their intensity over a few hours. A city block or two can make the difference between being in the thick of it, or, nothing happening. So, my primary advice is to suppress curiosity and walk away from where all the commotion is, and if you can't walk away, take shelter somewhere, but get off the street; then only when it is safe, get out.

The worst widespread effect I saw was the near total breakdown of the (then landline) telephone system; it was totally overloaded. This was in the days before cellphones (the late 60's/early 70's). I doubt that our cell phone system is any more robust, perhaps even less so.

Locally, in Baltimore, a short while back, there was an episode of serious civil disturbance. I watched it on TV. Different details, but the above thoughts still apply.