Raleigh mom Amber Petersen and her seven-year-old daughter were spending a cozy morning in bed on Thursday. As Brooklyn played a game on Roblox, a top gaming site for kids, Petersen read out loud from a chapter book.

But the quiet morning quickly took a different turn when Brooklyn suddenly stopped her mom from reading and showed her what had appeared on her iPad screen.

"At first, I couldn’t believe what I was seeing," Petersen wrote in a Facebook post that's been shared more than 300 times since Thursday. "My sweet and innocent daughter’s avatar was being VIOLENTLY GANG-RAPED ON A PLAYGROUND by two males. A female observer approached them and proceeded to jump on her body at the end of the act. Then the 3 characters ran away, leaving my daughter’s avatar laying on her face in the middle of the playground."

In an interview, Petersen said she couldn't believe what she was seeing.

"I was just completely shocked afterwards," she tells me. " It took me an hour ... I wanted to call the police."

She showed the graphic pictures to a physical therapist, who was in her home providing therapy to her son and who burst into tears.

"She starting crying hysterically, she was so triggered by it," Petersen said.

Roblox responds

Late Friday, Roblox released an official statement on the incident after we contacted the company.

"We were outraged to learn that Roblox's community policies and Rules of Conduct were subverted," it reads. "We have identified how this bad actor created the offending action and are putting additional safeguards in place to reduce the possibility of this happening again in the future. In addition, the offender was identified and has been permanently banned from the platform and we have suspended the game. We have zero tolerance for this behavior. Our work to ensure a safe platform is always evolving and remains a top priority for us."

Roblox, rated for kids ages 7 and up, is one of the most popular gaming sites for kids and teens. As Business Insider reports, the site has 56 million monthly players and a "mostly-teenage base of developers." A few of them have earned millions of dollars.

'It felt so personal'

Brooklyn had taken great care to design her avatar to look just like her.

"She invested a lot of time," Petersen said. "She earned money to get credits to buy houses and different accessories for her world. She's built this up. She has fun living in this little world. It's not simply a game. I feel like she identifies so much with it. And to see somebody do something to her avatar like that ... it felt so personal. It felt so real."

This isn't the first time parents and others have warned about images and storylines on Roblox. Last year, in the United Kingdom, at least one school raised concerns about what appeared to be a sex room with naked characters, according to the Express newspaper.

Reviews on Common Sense Media also raise alarms.

"I have been on the fence about this website until today," wrote one parent. "Today, I blocked the website from my son's computer and uninstalled it from his iPad. A hacker replaced kitten wall paper in a game with anime porn. Because of this I would say it is not safe for children."

Privacy settings had been set

Petersen said she thought she'd done all she could to protect her daughter from more adult content.

"We had set up all of the privacy settings and somehow things got reset," she said.

Her daughter may have deleted the app when her iPad was running out of space, only to download it again through the cloud.

"When you don't have your cloud set so you have to have a password to re-download stuff that's already downloaded, it's going to reset to factory settings," she said.

The incident happened, Petersen said, when Brooklyn used the search term "house" to find a a game that involved a mansion that she'd learned about on YouTube.

"That one was one of the more popular ones," she said. "It popped up first on the search lines. And she went into that and that's when it all happened. A simple search for 'house.'"

Brooklyn went outside the virtual house to find a playground, which she was exploring. That's when everything unfolded.

'Pictures don't do it justice'

"The pictures don't do justice to what the scene was," Petersen said. "The boys were literally throwing her on the ground. And when the character would try to run away, they would pick her up and throw her back down and do what they were doing."

Then a female avatar, who appeared to be wearing stripper clothes, Petersen said, would get on top of her daughter's character so the other characters could continue.

"It was the most horrifying thing," she said. "I was completely at a loss for words and I sat there just frozen and thinking, 'oh my god.'"

'Dangerous situation'

Petersen said she's sharing her story because she wants other parents to know about potential dangers on the popular app. In the last day, she's had some tough conversations with her seven-year-old.

"I had to talk to her about rape," she said. "I had to talk to her about consent. She's seven. I was not ready to have that conversation with her."

She said her daughter has been raising some questions, but otherwise seems to be doing fine. At the moment, she has no desire to get back on Roblox - and Petersen isn't sure if she'll ever let her.

"She's proud of herself that she's creating awareness about this," Petersen said. "She is helping other kids from seeing this stuff."

And Petersen said she sees the benefit of games like Roblox, but parents need to be careful. After posting on Facebook, other parents have shared their kids' troubling experiences on Roblox.

"I had no idea," she said. "For as popular as this app is, the fact that there has only been one viral story about the sex room thing ... parents have got to know that this wasn't a fluke thing. This is a dangerous situation and there are lots of people who have told me different stories."