PELL CITY, Ala. -- Jennifer Sellers likes to surround herself with memories and pictures of her daughter Sydney. The mother and daughter appeared to be as close as any could be.
"We did everything together, absolutely everything," Sellers told CBN News. "[We] went and got our hair done together; we did nails together; we did Wal-Mart together."
"I can't think of a single activity that we didn't do together except maybe her homecoming dance," she said.
But Sydney had secrets that she kept from her mom. Those secrets eventually led to tragedy on December 7, 2014.
That was the day Sellers found her teen daughter hanging from a belt in her bedroom.
"It was such a shock that I opened the door and I said, 'Sydney, that is not a funny practical joke,'" she explained.
Only it wasn't a joke. It was real.
"I immediately ran into the room," she said. "I didn't have the strength to pick her up; that's when I started screaming for my husband he picked her up. I cut her down. We laid her down on the ground and he immediately started CPR and I called 9-1-1."
But it was too late. Fourteen-year-old Sydney Sellers was dead.
Unraveling the Truth
Sellers, who works as a child advocacy attorney, struggles to understand why her daughter committed such a drastic act, especially since she had shown no signs of depression or trouble.
Even the morning of her death, Sydney had gladly attended church with her family.
"We went to mass, really proud that that was her first day as an altar server. So we were just excited," Sellers recalled. "She's in the robe, and she's going to be up on the altar. She did a great job."
As word spread of Sydney's death, her family learned from friends that she had been bullied at school. And the funeral home found cuts on her body, indicating that she had been cutting herself.
But nothing prepared the family for an online conversation they discovered on Sydney's smartphone.
At the time of her death, Sydney and a stranger had been messaging one another on an app called "KIK."
The subject was "erotic asphyxiation," or breath control play, which is the intentional restriction of oxygen to the brain for the purposes of sexual arousal.
Sellers said she's been married for 17 years and had never had a conversation with her husband like the one her daughter was having with a perfect stranger.
"I started looking and there was a conversation happening at the moment she died between her and a person who purported himself to be a teenaged boy and it was disgusting and he was giving her instructions of things to do," she said.
A Predator's World
Many teens log onto the Internet from the privacy of their bedrooms via mobile devices like a cell phone or table, and they often connect with people they don't even know while their parents are completely unaware.
Experts say it's the perfect environment for sexual predators.
"Predators are everywhere on the Internet," licensed family therapist Dr. Linda Mintle said.
"They know which sites kids tend to populate and go to and they pose as someone that a child might easily talk to," she explained.
Smartphone apps are often the weapons used to target kids.
"They know how to lure these kids into what looks like harmless things and get them talking and get them interested," Mintle explained.
"And if you're a young teenaged girl and you don't have a boyfriend and you're not liking your body too much and some guy starts talking to you online and tells you how beautiful you are and starts saying things to you, you're probably going to follow that trail," she said.
CBN Technology Contributor Caleb Kinchlow said parents need to realize that their teens are living in an entirely different world through social media.
He said there are several popular apps that teens use to connect on the Internet, often with strangers.
"Facebook is not the most popular app like it used to be," he explained. "Now it's Instagram, Snapchat, Oovu, Kik, Vine."
He said teens are more willing to share information via these apps that they normally wouldn't be comfortable sharing, including nude pictures and mature content.
Sellers said the man that Sydney was chatting with the night she hanged herself could not be traced because the "Kik" app allows users to connect anonymously.
Search it Out
Still grieving, Sellers now spends a lot of time talking to troubled teenagers and encourages parents to keep up with their kids' lives, something she said she regrets not doing with her own child.
"I had gotten complacent," she admitted. "My husband had gotten complacent. She went to school, she came back, she did her work, she made great grades, we figure we were good there."
"You need to talk to your kids to find out who they are growing into as people," she urged.
Mintle said parents also need to monitor their kids' Internet activity on a regular basis.
"They need to be able to look at every device and say -- is there a way to access the Internet from that device?" she said. "Because a lot of people don't think about an Xbox being able to get on the Internet from there. So you need to think about what devices do we have in the house? How is the access set up and what are the settings?"
"Most parents are fine if their kids run off on their tablets or their phones for an hour before they have to get in the shower and go to bed. They're not monitoring that," Sellers said.
"If you bought that phone, if you pay for that phone, I don't care what they say about their privacy," she said. "That is your property; you have a right to know what's on it. Search it out," she added.
It's a move that, while unpopular, may just save a life.