It's a week after the fire, and I cannot find articles with updated information. Which is weird to me, as you can see in the picture in the OP what looks like multiple security cameras (the black dots on the ceiling). I would expect that there are multiple views/angles showing the person(s) who caused the fire. I'm going to take the media silence as a likely indication that the arsonist(s) are not the Trans-Hating MAGApublicans that media people are looking for.
Fixed a typo