I read a book a few weeks ago called One Second After. It's about what happens in the US, primarily in one small town, when some unamed enemy sets off a number of Electro Magnetic Pulse weapons over the country. All electrics are fried. So next to no transport, lighting, power, comms...almost everything is dead.
It is chilling how convincing the collapse in 'civilised' behaviour is portrayed and the rule of law goes out of the window. New rules are the norm. Brutal laws. Severe punishments. People who were upstanding members of the community revert to being judge, jury and executioner.
In one case a couple of relatively young guys are caught stealing and dealing drugs. Their 'trial' lasts a few minutes. The sentence is carried out when they are dragged out to the local basketball court and shot in the head in front of cheering God fearin' town folk.
I was honestly chilled reading that at the time at how society can revert to carrying out such barbaric acts so quickly. It's positively medieval.
You're already there, my friend.