Piezoelectric or static electric discharge combined with exceptionally dry tinder or combustible material especially in very dry air may initiate a fire. Fine airborne dust particles agitating against a structure with some inherent electrical capacitance qualities or even compression of ground minerals in Earthquake zones can cause electrostatic and piezoelectric discharges.

I suspect that even nuclear fallout in a very dry environment with the ability to ionise ground materials could potentially also generate electrical discharges as well.