[Koko Ed]

This also isn't the first time something like this has happened. Way back in 2009 a guy committed suicide by cop in Centennial Park during the Einstein Finals. Fortunately the incident occurred a couple of hours before the teams were let out to go to the afterparty.
Also in 2012 there was a mass shooting at a medical clinic across the street during the Pittsburgh regional (2 people shot dead) that caused a lock down on the event and an evacuation of the people in the clinic to the arena. They just did extra practice matches til the all clear was given.