A Chicago girl, aged 15, was apparently sexually assaulted by five or six men or boys on the Facebook Live, and roughly 40 people have watched the live video, but none have reported the attack to police, the authorities said on Tuesday.

The video marks the second time in recent months which the Chicago Police Department has investigated an apparent attack that was streamed live on Facebook. In the month of January, four people were arrested after a cellphone footage showed that they allegedly taunted and beat a mentally disabled man.

The department’s spokesman Anthony Guglielmi said that, the police learned about the latest alleged attack when the girl’s mother approached the head of the police department, Superintendent Eddie Johnson, on the late Monday afternoon as he was leaving a department station in the Lawndale neighborhood on the city’s West Side. She also told him that her daughter had been missing since Sunday and showed him screen grab photos of the alleged assault.

He said that Johnson immediately ordered the detectives to investigate and department asked Facebook to take down the video, which the Facebook did.

Bastin Schweinsteiger moves to Chicago Fire

On Tuesday, Guglielmi said that the detectives found the girl and reunited her with her family. He said the girl told to detectives that she knows at least one of her alleged attackers, but it remained unclear how well they knew each other. He also said that the investigators are questioning several people, but no one is considered a suspect yet and no arrests have been made in the case.

He also said that Johnson was visibly upset after he watched the video, both by the video’s content and the fact that there were “40 or so live viewers and no one thought to call authorities.”

Guglielmi said by an email that, the investigators know the number of viewers because count was posted with the video. To find out who they were, the investigators would have to subpoena Facebook and would need to “prove a nexus to criminal activity” to obtain such a subpoena.

A spokeswoman for the Facebook, Andrea Saul, said that she had no specific comment on the Chicago incident but that the company takes its responsibility to keep the people safe on Facebook very seriously.

Mrudula Duddempudi.