For anyone who might have missed it, a poster gave a terrifically helpful link to the Georgia State Association's 2011 training video on the topic of "Fighting". Included is the advice mentioned above that things like this don't just happen all of a sudden, that there are identifiable precursors we should be alert for to keep stuff like this from happening.
This is a great resource for any association meeting.
Link:
http://http://www.ghsa.net/basketball. Scroll down to 2011 Training Video.