The proof of it showed up on YouTube. It’s called the Choking Game, the Passing Out Game, and many other names.

Last Thursday, the Stockton High School principal received a tip about a video of a 17-year-old male student playing the game with a group of students in the school's locker room.

Several videos on YouTube show kids falling to the floor, unconscious, on purpose. Kids play the Passing Out Game or Choking Game for the rush created by a lack of blood flow to the brain when their air supply is cut off.

“I've heard this from my friend. She said the boys get down on the ground and squat down and hold their breath for 30 seconds, and they punch them in the chest until they pass out,” said Emily Meeks, a Stockton High School student.

“They do it around a bunch of people, and it's a game,” said Kaley Rogers, another student.

High School officials were shocked to find out how popular the game is, and that it happened in a school locker room just last Wednesday.

It was Thursday evening that school officials saw the video on YouTube. It's now been removed but they know it was here in the high school football boys locker room because they recognized the red wall and the outline of the state behind the person playing the game.

“The student had bent up and down several times until they kind of got light-headed, and when that happened, standing up against the wall, another student came up and pushed on his chest, and at that point, he just slid down the wall, actually hit his head on a chair, and then he laid there for probably three or four seconds before coming to,” said Principal John French.

French says he spoke to more than a dozen students on Friday who tried or witnessed the game about the dangers they face. If the oxygen supply is cut off for too long, students could experience brain damage or even death.

Multiple videos on YouTube also tell of that reality, showing kids who died from playing the game.

“I think they just don't realize the dangers involved. In their eyes, they're not doing anything illegal; they're not speeding, they're not drinking, they're not doing drugs, and they just don't realize what could come of it, and they think it's funny,” said French.

The school sent out a telephone message to all parents in the district, and encouraged them to research it online and talk about the so-called game with their kids. They say, since the message went out, they've been notified of more kids who've tried the game.

Administrators hope communication and education can prevent anything tragic from happening.

Parents can watch for certain signs to know if their child has been playing the game. Those include bloodshot eyes, marks on the neck, severe headaches, belts or ropes with unusual knots, and ropes tied to furniture.