Shiro will definitely look into this. His questions will be along the lines of 'who was in the area prior to the fires started?', 'is there any patterns'. But, he'll also ask to look at the areas burned themselves and try to suss out any scents as a wolf.

He'll look for culprit scent, of course. But he'll also be looking for the scent of any spell components that might have survived the burning or just have been dropped at the scene. As he conducts his investigation he'll also offer his assistance in tending to anyone wounded by the fires.