I'm going with: never attribute to malice what can be explained by ... an incredibly complex system that can fall over even if no-one's being stupid. I would want very strong evidence before I believe this is an attack.
I remember the day when the Swiss railway power network went down for a day (in 2005) because one power line was down for maintenance and someone pressed the wrong button and produced a short circuit somewhere else. It's a bit like the incidents in planes were one engine has a problem and the crew shut down the other one by mistake.
There is precedent for major power outages, a huge majority of which are not malicious: https://en.wikipedia.org/wiki/List_of_major_power_outages
I remember the day when the Swiss railway power network went down for a day (in 2005) because one power line was down for maintenance and someone pressed the wrong button and produced a short circuit somewhere else. It's a bit like the incidents in planes were one engine has a problem and the crew shut down the other one by mistake.