I haven't seen any updated reports yet today, but CBS is reporting there were 'three incendiary devices found' at the scene. At least one window was obviously broken out in one of the photos. Early news reports often have the details mixed up. One news video showed a street interview of a neighbor who said he heard gunshots at 7:30 am, which doesn't seem likely at a KH; maybe he was mistaken about the time.
I am upset by this story and will be very interested in knowing the backstory.