Just listened to a report of a church in South Carolina, they played up the arson angle and at the very end they reported that storms were rolling through the area and a witness heard a loud boom indicative of a lightening strike. YMMV
I hope that one was lightning.
Could be that people are aware that same church was burned to the ground in 1995 by a couple of klan members who later confessed.
There's a lot of unstable people out there though.
Remember the string of church burnings in east TX in 2010 that turned out to be committed by a couple of satanists on drugs?
https://en.m.wikipedia.org/wiki/2010_East_Texas_church_burnings