You'll be shocked when you find out that people had to pass through metal detectors and were not allowed to carry guns inside the event.
Nope. Open carry does NOT mean everywhere. It means you can be armed
as long as folks in charge of the location do not restrict it eg schools, sports events, rallies, airports, etc.
We need the Supreme Court to fix this ASAP. It's obvious that if the attendees had at least two AR-15s each then this event would have been 100% safe.