VACAVILLE -- A dangerous game targeted at teens ... with a deadly ending.
"In order to win the game, you have to end your life," said Caileigh Santos, a Florida resident with Bay Area ties.
Santos says she played the game.
The 12-year-old's innocent voice masks a scary reality.
The Blue Whale Challenge works like this: players are assigned a series of challenges over 50 days, from watching scary movies to self-mutilation. On the last day they're encouraged to kill themselves.
Caileigh says she was asked to play on Instagram and was threatened if she didn't.
"...find out your location, go after you and your family, so I was like, I don't really have a choice," she said.
Her first task?
"Carve F 57 in your leg," she said.
Caileigh says she only got through the first of 50 days before her mom found pictures of the cuts on her phone...
"Holy crap, I was like 'This is Caileigh.' I didn't know what to do I was like, 'oh my gosh,'" said Caileigh's mom, Melissa.
It's alarming stories like this that has the Vacaville Unified School District on high alert.
"We want to help parents as much as we can, if we hear something, we want to share it," said Jennifer Leonard with the Vacaville Unified School District.
The district hasn't caught students playing it, but parents are being warned to be aware -- and it's appreciated.
"It gives us an opportunity to open up a conversation with our child to talk about things," said mom Theresa Kenui.
Instagram is taking its own steps to protect app users.
A Blue Whale challenge search shows a prompt before the photos. It offers mental health services.
The Tracy Police Department also warns about the game in a Facebook post.
It's all in an effort to keep teens safe.
"I don't want anything like that to happen to my kids," said mother Sheen Mack.