A teenage girl’s sexual assault was broadcast on Facebook Live, and the dozens of people who watched the stream did not notify authorities.

According to CNN, Chicago police are attempting to identify each of the alleged attackers. The video, which has been taken down from Facebook, shows between five to six males assaulting the 15-year-old. Police spokesman Anthony Guglielmi said the victim knew at least one of the suspects shown in the footage. Several of them are identifiable As of Tuesday, no formal arrests have been made.

Police became aware of the video after the girl’s family reported her missing. The victim’s mother reportedly approached Chicago Police Superintendent Eddie Johnson on Monday, stating her family had not seen the girl for 24 hours. She also presented Johnson with screenshots of the Facebook Live stream, images that confirmed at least 40 people were watching it live. Authorities said none of the viewers called the police.

The victim has since been reunited with her family and is currently receiving medical treatment.

Unfortunately, this kind of incident isn’t new for Chicago police. In January of 2017, four people were arrested after they tortured a special needs teen and streamed the assault on Facebook Live.

"Crimes like this are hideous and we do not allow that kind of content on Facebook,” A Facebook spokesperson said, as reported by CNN. “We take our responsibility to keep people safe on Facebook very seriously and will remove videos that depict sexual assault and are shared to glorify violence."