Siblings lock themselves in a bedroom for 54 days, documenting it live on TikTok in new docuseries

It was a bitter custody battle that went viral on TikTok. Now, it's all coming to the surface in ABC News Studios' latest docuseries, "The Nightmare Upstairs: What Happened to Ty and Bryn?"

The two-part series documents the case of two siblings, Ty and Brynlee Larson, who barricaded themselves in a bedroom for 54 days to escape the reunification process with their biological father.

On The Red Carpet spoke with co-director and executive producer Caitlin Keating about the series.

Keating describes the barricade, which was livestreamed on TikTok day and night.

"They had to cook together. They had to break, they have to break a wall down to get to the bathroom, because they said they were so scared to walk outside their bedroom to go into the bathroom, and they could be taken, you know, during those, just walking a few feet. So they just, they tried to survive, you know?"

Before the barricade, Ty and Bryn accused their father, Brent Larson, of sexual abuse, which he denied vehemently. The district attorney never charged him with a crime, yet the kids still did not want to end up in his custody.

Keating explains how the reunification process was meant to happen. "After Brent was accused of abuse, he went to the court and claimed parental alienation, saying that Jessica Zahrt, his ex-wife, had essentially brainwashed, manipulated the children into being afraid of their father and coming forward with these allegations. And the judge during that time believed the father and did think that Jessica was alienating them. So that is when he said that there was going to be a minimum of 90 days of no contact with the mom and uninterrupted time with him."

That's when the kids went live on TikTok to tell their story - to over a million viewers.

"They gained a loyal following of people who were chiming in on their live streams who were just supporting them, encouraging them," Keating says.

Without social media, the story wouldn't be what it is.

"I don't think Family Court is used to having social media now be a big part of a case that they're dealing with," Keating explains. "It's just, it's incredible and heartbreaking and so many different, you know, things to think that it took, it took this for these children, you know, to go on social media, but they were finally heard, you know? And the judge brought this to trial. And, you know, it's, I think we're going to see more and more stories too, of kids, of adults, speaking their truth for millions of people to hear them."

After a long custody battle, Brent Larson winds up making an unexpected decision. See how it all unfolds in "The Nightmare Upstairs: What Happened to Ty and Bryn?," streaming now on Hulu and Hulu on Disney+.

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