I have this scenario where the world was thrown into chaos by something and in this event, shortsighted governments launched assaults on numerous military and civilian targets, leading to the collapse of the society. It is a society with advanced robotics, cloning technology (not widespread and incredibly slow), and highly efficient and advanced farming technology following the depletion of all fertile soil roughly 1300 years prior. The plotline follows a clone who was given a false set of memories from a randomly generated backstory AI, which start from birth and end at age of 17. However instead of waking up in a sterile cloning facility which lines up with the medical facility the memories last recall them entering, they wake up in a mostly destroyed facility with little remaining of society.
What scenario takes out society across the continental US, Canada, and Mexico (unified under the Canadian government following the flooding of 40% of the landmass in the US and Canada, and 90% of Mexico) without taking out the robot-maintained power grids? We can assume that the facilities making clones have their own means of creating or acquiring matter to make clones.
Weapon technology in this universe ceased notable progression shortly after oil runs out in the year 2028 and the only notable technologies developed are railguns sized for the secondary armaments' of tanks and the removal of the Geneva convention on suffering.