Sandy's phone buzzed. The message read: "You might want to go check on your daughter."

Content warning: This post deals with suicide and may be triggering for some readers.

On July 4, 2017, Sandy Cadena’s 32-year-old daughter, Natasha, died by suicide after allegedly taking part in a dangerous online game.

Cadena, from Wichita Falls in Texas, told Times Record News she believes the people behind the ‘Blue Whale Challenge’ – which stipulates participants must complete 50 set tasks – are responsible for her daughter’s death.

Sandy alleges a woman named ‘Loretta’ pressured Natasha into carrying out a range self-harming activities, which culminated with her daughter recording her own suicide.

“Natasha was told to do hurtful things to herself,” she said. “She would cut herself, around her neck, other places, and then show this woman…

“These people pay top dollar to watch someone kill themselves,” she added.

Natasha began an online friendship with ‘Loretta’, who Cadena believes lives in France, while she was suffering from depression.

According to Sandy, the friendship soon turned sinister when ‘Loretta’ began pressuring Natasha to harm herself, she also started demanding money. By the time of her death, Natasha only had $7 to her name as she was sending ‘Loretta’ $300 a month.

‘Loretta’ then contacted Sandy and told her about Natasha’s death.

“Somehow she got my number,” Sandy said, “and she told me, ‘Hey, you might want to go check on your daughter. I think she just killed herself.’ I said, no way. But Natasha wouldn’t answer her phone. So we rushed to her apartment. She wouldn’t answer her door. When I reached for my phone to call 911, Loretta was calling again.”

As Crime Online reports, the ‘Blue Whale Challenge’ seems to have originated in Russia and may have already claimed the lives of 130 teenagers in the country.

After her daughter’s death, Cadena spoke to the Wichita Falls Police about the ‘Blue Whale Challenge’ and Sgt. Harold McClure told Times Record News that although the death had been ruled a suicide, the case was still open.

Sandy is now raising Natasha’s seven-year-old daughter Bella, she wrote in a recent Facebook post that “Bella Gracie is doing well” and seeing a therapist to help her understand her mum’s passing.

If you or a loved one is suffering mental health issues, Mamamia urges you to contact Lifeline on 13 11 14 or visit the Beyond Blue website.