This is bizarre to me. Have an inlaw that lives in Oakland. Last I heard he was living in a communal warehouse. He was into the burning man stuff and all that. Would not be surprised to hear that he was a victim. Although with Oakland being Oakland, there are many of these types of places in existence. Of course we would be the last to know if something happened to him. We do not keep up with that branch of the family.
some articles indicate that some of the people associated with the warehouse attended and/or worked on art for Burning Man. Hope your relative is OK.