‘The Biggest Loser’ 2016 Spoilers: Season 17 Premiere Sneak-Peek Video Reveals Contestant Tonsheia Grandison's Heartbreaking Story

"The Biggest Loser" Season 17 Spoilers — A sneak-peek video from the Season 17 premiere of "The Biggest Loser" teases the series' most emotional installment to date. (Pictured left to right: Lauren Clark, Vicki Clark, Hope Williamson, Colby Wright, Luis Hernandez, Roberto Hernandez, Sarah Gilbert, Robert Kidney, Felicia Bufkin, Whitney Clay, Tonsheia Grandison, Britney Anderson, Erin Grace Willett, Richard Hatch, Jacquelyne Kmet, Stephen Kmet.) NBC/Tyler Golden

We hope you have a box of tissues on standby because you’re definitely going to need them. On Friday, NBC released a sneak-peek look at its upcoming season of “The Biggest Loser” – and according to the minute and a half long video, things are going to get extremely emotional when the hit weight-loss series returns in 2016.

The competition, set to premiere Monday, Jan. 4, will kick off with the show’s newest host, Bob Harper, getting some intel on the contestants who are competing in the long-running series. But little did Bob know just how gut-wrenching contestant Tonsheia “Toy” Grandison’s story would be when the two began talking …

“How did you not protect your son?” Bob asks Tonsheia, who attempts to respond through uncontrollable sobs.

“I should have had my life together,” she replies.

"Biggest Loser" Season 17 Spoilers — "Biggest Loser" trainer Jen Widerstrom (left) motivates contestant Tonsheia "Toy" Grandison (right) during Season 17 of "Biggest Loser." NBC/Tyler Golden

According to the 36-year-old Georgia native, she was homeless at the time and staying with the mother of her friend Britney Anderson (who she’s partnered up with in the 2016 weight-loss challenge) along with her 13-month-old son. She had fallen asleep after putting him to bed when tragedy struck.

“Someone went out the back door and when they came in they didn’t shut it. And he woke up,” her voice cracks from the immense pain. But Tonsheia continues to tell the heartbreaking as everyone’s eyes begin to well up with tears. “He walked right outside and he drown.”

According to Tonsheia's “Biggest Loser” bio, the mother of four is determined to get in shape so that her children can follow in her footsteps of leading a healthy life.

"My biggest motivation for going on the show is to be a good role model to my kids," she says. "I want to get healthy and teach them a healthy lifestyle."

“The Biggest Loser” will air its Season 17 premiere on Monday, Jan. 4, at 9 p.m. EST on NBC.