Some might think sex trafficking is something that just happens in other countries. It's a growing epidemic in the city of Chicago.
Some experts say it is a dangerous problem that few people are aware of, and is hard to believe goes on so close to home.
A young Chicago woman who was caught up in a sex traffic operation shared her horrific story with FOX Chicago News.
To protect her identity, we are calling her Brittany. She told Jan her nightmare began when she was just 16 and on a night when she got into a heated argument with her parents.
“So I ran away from home and ran into a girlfriend of mine. She had informed me that I could come and stay with her and her boyfriend at the time, I said yes and it sounded like it was going to be a lot of fun, freedom. No parents, no problems," Brittany said.
Brittany said she went with the couple to a house we can only tell you is in the South Suburbs. She also said she only planned to stay just one night.
Once in side the house, her plan changed. Brittany says her friend's boyfriend took her to back bedroom and "that's when he forced himself on me. He raped me right then and there."
Brittany fought and tried to get out, but she was chained to a bed and locked inside a room. She says the boyfriend then told her "he was a pimp and was going to prostitute me out."
Brittany refused and tried to get away but couldn’t do so.
"They say it, you have to do it. If you don't, they'll kill you or they'll kill your family," she said.
Brittany said there were several others girls in the house, some even younger than she was. They were not allowed to communicate with each other but she could hear their screams through the walls.
"There were probably four, maybe five different bedrooms. Each room had a different girl and it would have a letter above the door and that's how he would tell the ‘John’ to go in that room."
As for her room, "All I had was a bed, there was a chain from the bed to my ankle and I had a coffee can cup which I had to use to go to the bathroom. He would throw us a sheet every now and again because the rooms would get pretty cold for us to keep warm with but yet again we were completely naked," Brittany said.
Brittany said she was held captive for more than three years, constantly sedated and injected with drugs, all while hundreds of "Johns" walked through the door.
No one ever reported seeing the young girls chained to these beds. No neighbors thought the constant traffic in and out of the house was suspicious.
"I worried about my mom a lot, wondering if she knew where I was? If anybody was looking for me, if the police were looking for me,” Brittany said. “A lot of times I would pray the swat team or officers would kick in that door. I wanted to go home but they never kicked in."
Brittany's story is real and it concerns people like Cook County Sheriff Tom Dart.
“People aren't understanding the magnitude of [sex trafficking] and seriousness of it," Dart said.
Dart said the sex trafficking industry is widespread in Chicago; it is hard to track the number of underage girls involved. Sheriff Dart said he has seen girls as young as 13 years old become victims.
According to the National Human Trafficking Hotline, Illinois is among the top 10 states it receives the most calls from and the Department of Justice recently designated Chicago as a "high-intensity area" for sex trafficking.
Once enslaved, many girls never make it out. Brittany never gave up. She eventually tricked one of her captors into letting her outside, and that's when she made a run for it and escaped.
"I want girls out there to know that there are people that are trying to help,” Brittany said. “There is help out there to get the strength like I did, get that will and get away."
Brittany is now 22 years old, and told Jan it took her a year to sober up after her three years of her drug induced enslavement.
She works with the Cook County Sheriff's office and Dreamcatcher’s foundation to help educate and rehabilitate other young women who share a similar story.
The US Dept of Justice has a list of resources on their website .
The public can also report human trafficking tips to this hotline: The Salvation Army STOP IT Program at (877) 606-3158.
Anyone with information can email tips directly to the Cook County States Attorney Human Trafficking Initiative at firstname.lastname@example.org.