Janya Williams, 18, allegedly sent her supervisor an anonymous message via TextNow Friday afternoon that said, "Mass shooting at 4pm location Lollapalooza. We have 150 targets."
The supervisor quickly contacted their supervisors and the Chicago police and the FBI were notified.
When the supervisor told the team about the threat, Williams allegedly told the supervisor that her sister had seen a similar threat on Facebook.
After the supervisor asked Williams to send a screenshot of the threat, she is accused of creating a Facebook account under the name "Ben Scott" and posting a message that said, "Massive shooting at Lollapalooza Grant Park 6:00 p.m." She then took a screenshot of the post and sent it to her supervisor, prosecutors alleged.
The FBI, however, reportedly traced the TextNow message back to Williams’ IP address and iCloud, prosecutors said
She allegedly admitted to faking the threats "because she wanted to leave work early," prosecutors said, and was arrested for felony making a false terrorism threat.
She was booked into jail and is being held on $50,000 bail.
Lollapalooza took place Thursday through Sunday last weekend.
Williams is scheduled to be in court on Monday.