The fires in Greece simply overwhelm my sense of comprehension. Has this happened before now?

Yes, arsonists have lit forrest fires in Greece before. Never before to this extent, where the fires have killed around 60 (estimated) victims. When I lived in Athens, around 1986, maybe a year before or after, I remember the mountains east of the city being smokey and then days later, the black charred mountain side. I do not remember the arsonist ever getting caught, I think he (or she) got away with it.