Police believe an incident that occurred Tuesday was just the latest episode in which at least one person was seriously injured and one department store was vandalized.
Police say it all began just after 5:00 p.m. when high school kids from three schools were kicked out of The Gallery for being disruptive. Police say that's when the teens began acting like a flash mob.
"Upon leaving The Gallery, approximately 50-100 individuals were running in and out of traffic, pushing people down, snow ball fights, stopping cars," said Lt. George Ondrejka, Philadelphia police.
One woman came upon the mob as they were running through 13th and Market Streets, saw the look on some of their faces and knew there was going to be trouble. She said the teens looked angry and were allegedly acting like they wanted to hurt someone.
She went on to say in an instant the mob knocked one kid to the ground and as he laid bloodied, she says one of the girls in the crowd kicked him in the head, even as the police stood nearby.
Police promptly arrested the girl and rushed the boy to the hospital.
Authorities say the mob also ran through the Macy's department store across from City Hall, ransacking the place and causing several hundred dollars in damage.
Investigators say Tuesday's incident is the most recent flash mob event in Center City and they think it may have been organized through Facebook or Myspace.
"We're seeing more and more as the school year goes on, these kids are being released from school, they congregate in The Gallery area, and then when they're moved along, that's when they run wild," said Lt. Ondrejka.
Police say it's unclear if the boy that was hospitalized was part of the group or got swept up in it.
Right now at least 19 males and one female are in custody. The girl is being charged with aggravated assault. The males are facing charges including vandalism and criminal mischief.
