Seth Abramson has more. There’s a lot more graphic video out there. The shooter I saw had fallen, and sprayed the vicinity with his rifle after someone tried to take it from him. All the injured people appear to be as white as the shooters from the videos on Twitter.
There is no mainstream media coverage yet.
If you don’t want a graphic reminder of just how ugly humans can be avoid the comments on those tweets, and others reporting on the incidents. There are said to be multiple shooters (video shows different-looking ones).