Dad Warns Parents After Son, 12, Dies from 'Blackout Challenge': 'Check Out' Your Kids' Phones

"This is a weapon in our home that people don't know about," says Haileyesus Zeryihun

Colorado father Haileyesus Zeryihun is speaking out about his son Joshua's death in the hopes that other parents can stop internet trends like the "Blackout Challenge" from harming their children.

"Check out their phones," Zeryihun, 46, tells PEOPLE in this week's issue. "It's not about privacy — this is their lives."

Zeryihun's nightmare began on March 22, 2021, when his son Caleb went searching for his twin brother Joshua, 12, in the family's Aurora, Colorado, home. Caleb found Joshua lying on the floor with a shoelace wrapped tightly around his neck.

Tragically, Joshua ended up spending 19 days on life support before he was pronounced dead on April 10.

"We prayed so hard for him to wake up," says Zeryihun, who owns a medical transportation company. "It was just hard."

An actively involved father, Zeryihun already had the dangers of the internet on his radar. He monitored his kids' apps and deleted TikTok — where some of the challenges have gone viral — from their phones after he read that TikTok wasn't age appropriate for his boys. Still, "videos are everywhere" online, says Zeryihun, and Joshua was the type of kid who "liked to explore and try new things."

Joshua Zeryihun (in a framed photo to the left) "wanted to be an actor," says his father Haileyesus (second from left, with, from left, sons Abenezer, Nathan, held by mom Zeleke, and Caleb). courtesy Haileyesus B Zeryihun

Joshua learned a lot of good skills from those videos — including the guitar, soccer and cooking — but at some point he also learned about the "Blackout Challenge," in which participants starve themselves of oxygen until they pass out.

After Caleb saw what the challenge did to his brother, he and a neighbor tried to revive him with CPR to no avail. An ambulance rushed Joshua to the local hospital before he was airlifted to Children's Hospital Colorado.

"The doctors were telling me there's nothing they could do, and we have to let him go," Zeryihun recalls of his son's final days. "I couldn't accept that."

Joshua Haileyesus.

He begged the physicians to try to save his son's life.

"I felt like my son is drowning and trying to give me his hand, and I need to go reach out and pull him up," Zeryihun says. "For me to just give up, I felt like I'm just walking away from a drowned kid."

For more on dangerous TikTok challenges — including expert advice for parents — pick up the latest issue of PEOPLE, on newsstands Friday, or subscribe here.

It's a heartbreak he wants no other family to experience.

"This is deadly. This is a weapon in our home that people don't know about," he says of video challenges. "I want parents to know what their kids are doing."

To that end, Zeryihun suggests that parents watch the videos their kids view on platforms like TikTok and YouTube; review their kids' apps and user history; and start a dialogue about the content they're consuming.

He also asks that parents tell their kids about Joshua.

TikTok declined to comment to PEOPLE for this week's story about alarming challenges online, and the number of users injured performing challenges is unknown, but in an updated safety policy released in February, the company says, in part, "We do not permit users to share content depicting, promoting, normalizing or glorifying dangerous acts that may lead to serious injury or death."