Some residents of the San Bruno neighborhood that went up in flames had supposedly reported smelling gas, and PGE reportedly investigated and found nothing. Something similar, affecting only one house, killing one and burning another severely, occurred in 2008. That situation was handled stupidly by all involved, including the residents: if you smell gas, you get out and air the place out, and if you can't get rid of it, you stay out and call the gas company and the fire department. But PGE's "stupidity" was too stupid, in my opinion, to be stupidity.
The fact that PG&E apparently didn't learn anything from this earlier incident is also suspicious. How could they not evacuate the neighborhood until the issue was settled? Did they send out someone who couldn't smell gas?
So, something besides gas smells about this situation. One possibility is that it was "blind" terror, a "black op" where inducing terror is all that matters, and there is no reason to blame it on a particular group. Perhaps it was an experiment to see how those directly affected would respond, and how the city, state, and nation would respond. There are many possibilities, so I won't even try to list them. But then, I could be wrong, and it could just be stupidity on the part of people who feel a little too secure in their jobs, and on the part of those who smelled gas yet accepted the gas company's conclusions that there was no problem.