Two girls attacked another girl at Roger C. Sullivan High School on the Far North Side.
The fight happened last Thursday during a biology class. Two sisters, one 17 years old and the other an adult, 18-year-old Sara Mejorado, are charged with misdemeanor simple battery.
At one point the victim's head may have been slammed on the table. The victim suffered cuts, bruises and a concussion, her mother said.
Sources said the victim called one of the attackers a name. Students described the victim as a friendly girl.
"She's actually really nice, I have no idea why it happened, I think it's real mean what they did to her," student Tiana Vonner said. "But shes a real sweet girl." One student described the excitement the fight caused.
"There's a fight, they're beating up a girl, it's like wow," Evelys Riverra said. "(The teacher) wouldn't let us leave the classroom. He closed the door and told us to ignore it. Screaming just kept coming for like 10 minutes."
In a statement, Chicago Public Schools said, "Chicago Public Schools does not tolerate violence among students in any way. The two students involved in this incident have been suspended from school with further discipline pending."
Some students and a parent said fights like this occur all the time.
"It has been too much fighting," said Phyllis Lopez, a parent. "For the last three years I had numerous kids, nieces and nephews, we had to pull out because of gang activity."