IIRC, this is not the first time there was a fire in that building.
Huge building. I’d assume fires are not exactly surprising.
That it’s in one corner seems innocuous. A whole floor or multiple locations would be more suspicious of deliberation.
Nope, not the first time, likely won't be the last. That's a residential floor, IIRC that's the same floor Chris Farley used to live on.
Oddly, all the commercial spaces in the Hancock Building were required to upgrade to include sprinklers while the residential floors were not.
I imagine they're going to change that one of these days.