From the Las Vegas Sun:
A swarm of teenagers reportedly went charging through crowds at the San Gennaro Feast grounds late Saturday, startling families and drawing the attention of Metro Police.
Chatter about the melee flooded Facebook and Twitter.
"I feel so bad for the families that go to San Gennaro to have a good time and end up being surrounded by a bunch of disrespectful teenagers," user @Miaadaniel tweeted. http://www.lasvegassun.com/news/2014/may/11/teens-cause-disruption-san-gennaro-feast-saturday-/
My guess it wasn't a bunch of Italian kids running amok on the frounds.