Police say the wave of violence started at a block party around 9:30 p.m. Saturday at Broad and Susquehanna and headed south, with upwards of 200 young people on a rampage.
"We were walking down the street then, out of nowhere, there's a hundred kids," said Rajiv Sainath. He and a group of friends were on Green Street near Broad when they were engulfed by the mob.
"By bad luck the head of our group and the head of the mob reached the corner of Broad and Green at the same exact time," said Sainath.
He said some girls in the mob yelled at them to run away and some of Sainath's group did just that. He was among those who didn't.
Now, Sainath has a sneaker imprint on his forehead and numerous cuts and bruises.
"We tried to get away but kids would grab our shirts and starting hitting us in the back of the head, in the side of the head," Sainath said.
Rajiv's friend Emily Guendelsberger was most seriously injured. She's in the hospital with a broken leg that will have to be surgically repaired. Sainath said she also had some minor liver damage.
"The girls in the mob formed a ring around her so the guys wouldn't hurt her," said Sainath, but surmised Guendelsberger was hurt when she was initially pushed down.
Guendelsberger works for the "A.V. Club" portion of the satirical "Onion" newspaper. "A.V. Club Philadelphia has setup a section of the website for people to donate to help her pay for medical costs.
There is no word yet of any arrests in this incident.
The mob also attacked other people at Broad and Fairmount and 15th and Chancellor. Three people were arrested in that case.