"No one was in the bedroom with her when this happened, so there was no one there to save her."
CHESTER, Pennsylvania (WPVI) -- A Delaware County family is warning others following the loss of their 10-year-old daughter after she took part in a dangerous challenge she saw on a popular social media app.
It's the latest child death to be linked to a social media dare dubbed the "Blackout Challenge," where you hold your breath until you pass out.
Here's what this young victim's mother wants you to know: it happened to her good, smart kid, and it happened under her own roof while the family was home.
"She was a butterfly," says Tawainna Anderson, who just lost her 10-year-old daughter, Nylah. "She was everything. She was a happy child."
Nylah is described as fun and bright. She spoke three languages. Like most tweens, she was on social media and participated in the recently popular, viral, and extremely dangerous "Blackout Challenge."
"It's a challenge to see how long you can be breathless, or hold your breath in," said Dr. Mindy Dickerman, the Associate Division Chief for the Pediatric Critical Care Division at Nemours Children's Hospital. "It can result in a strangulation."
Doctors say Nylah was at home when she tried the trend.
"She happened to be in her own bedroom of her house, with her family at home," said Elizabeth Wood, a licensed clinical social worker with the Division of Critical Care Medicine in the PICU at Nemours Children's Hospital. "But no one was in the bedroom with her when this happened, so there was no one there to save her."
Nylah's family is in a state of shock. They rushed her to Nemours Children's Hospital, but she didn't make it.
"I'm so hurt," said Tawainna. "This is a pain that won't go away. It's at the top of my throat. I am so hurt."
Medical authorities say the lack of oxygen can lead to cardiac arrest and other medical dangers.
"It can cause significant organ damage, including brain damage, even death," said Dr. Dickerman.
Nylah's mom warns parents to pay attention.
"Make sure you check your kids' phones," she said. "You never know what you might find on their phones. You wouldn't think 10-year-olds would try this. They're trying because they're kids and they don't know better."
Doctors say the best way to start a conversation with your child is simply by asking what they're watching on social media.