Mary Cole said goodnight to her 14-year-old daughter around 10 p.m. on Sunday, November 24, 2002, just before leaving to work the night shift at the Tiffin Developmental Center. It was the last time she saw her daughter alive.

Cassandra “Cassie” Cole, who lived at home in Tiffin, Ohio, with her mother, stepfather, and two younger sisters, was sleeping in the rec room that weekend.

“She was taking one of those family classes at school where they have you take care of a baby doll that cries in the middle of the night,” Mary told Dateline. “So, she was sleeping in the rec room so she wouldn’t disturb anyone.”

When Mary walked into the room to say goodnight, she noticed her daughter didn’t have an alarm clock.

“I gently woke her and asked how she was going to wake up in the morning for school,” Mary said. “She said her [stepfather] was going to wake her up, which was odd to me. He didn’t normally do that. They hadn’t been getting along. I left for work feeling all out of sorts.”

The next morning, Cassie’s stepfather called Mary to tell her their daughter was missing.

“I was like ‘what do you mean she’s missing?’” Mary and Cassie’s stepfather were married for nine years and he adopted Cassie when she was very young.

Mary arrived home from work early Monday morning and checked the rec room where she last saw Cassie.

“That baby, the baby doll from her class at school, was still in the carrier. Hadn’t been moved,” Mary said. “She was serious about that baby and the class assignment. She wouldn’t have just left it alone.”

Mary waited until about 8:30 a.m. to call Columbian High School, where Cassie was a freshman.

“I called then because I knew that’s when they took attendance,” Mary said. “They told me she had been marked absent. That’s when I knew something was wrong. Where could she be?”

For months, Cassie’s family searched for her.

“I stalked the high school lunch period every day,” Mary told Dateline. “I would drop my 8-year-old off at school, load up the 5-year-old in the car, get her a snack, and we’d go to all the places the high schoolers liked to go on their lunch break. Like the pizza joint and the donut shop. Every day, I watched for Cassie. Hoping for a glimpse of her. But I could never find her.”

Cassie was initially classified by the authorities as a runway.

“No. She would never run away. She didn’t fit that profile,” Mary said. “She wasn’t a troublemaker and wasn’t having a hard time with life, I don’t see any reason why she would want to run away.”

Mary said Cassie was “very likable” and never met a stranger.

“As soon as you met Cassie, you would be friends,” Mary said. “That’s just how she was.”

Mary said Cassie had many friends, liked hanging out and listening to music and loved to swim.

“She loved being in the water,” Mary said. “She was like a damn dolphin.”

Cassie’s older brother, Nate Jumper, who had already moved out of the house at that time, agreed with his mother that his teen sister would never run way.

“She would not be one to run away. At all,” Nate told Dateline. “She would stay and stand her ground before she ever ran away from her problems.”

Christmas Eve, which was also Cassie’s birthday, came and went. Cassie would have turned 15.

“It didn’t feel right though,” Mary said. “She’ll forever be 14 to me. Really, she’ll always be my baby girl.”

Months passed but Mary wouldn’t give up searching for Cassie and checking in with authorities every day on possible leads.

“But the days turned into weeks and the weeks turned into months and still nothing,” Mary said. “I just couldn’t find my girl.”

On March 20, 2003, as Seneca County was thawing out after a long winter, Mary got the news she had been dreading.

A group of locals who were gathered at a popular hangout spot at the old Abbott Bridge near the Sandusky River made a horrific discovery

around 2 p.m., according to Sergeant Kevin Reinbolt with the Seneca Sheriff’s Office.

A badly decomposed body was found along the banks of the river just over the county line from the city limits of Tiffin into Northern Seneca County near Fort Seneca.

It was Cassie.

“My heart just stopped. It was the worst thing I could have heard,” Mary told Dateline. “I had a bad feeling early on. A bad feeling something terrible had happened to her. But nothing can prepare you for this.”

Sergeant Reinbolt told Dateline the Lucas County Coroner's Office performed an autopsy and released the cause of death as drowning.

“Her death has never been ruled a homicide, but we have been investigating it as a suspicious death,” Sgt. Reinbolt said. “We’re not ruling out foul play as we continue to look for answers to the circumstances surrounding her death.”

Authorities believe Cassie was dead the entire four months she was missing and that her body may have been placed by the river. But Sgt. Reinbolt told Dateline they also received tips that there had been sightings of Cassie in different areas of the county during that time.

“Multiple people came to us with Cassie sightings,” Sgt. Reinbolt said. “But we never had any concrete evidence that she was seen alive during those four months.”

Sgt. Reinbolt told Dateline hundreds of people were questioned, and some even took polygraph tests, but passed with flying colors, and a suspect has never been named.

“We’ve had our suspicions, we still do, but there’s just not enough evidence to support an arrest,” Sgt. Reinbolt said. “We want to give the family closure, but we’re at a standstill. There’s just not enough information to move forward.”

Cassie’s brother, Nate, firmly believes his sister was murdered, that her body was concealed for months and then placed at the site near the river. But he told Dateline that his anger has turned to frustration and he just wants closure for his family.

“It’s time for it to be wrapped up. To be done,” Nate said. “This has destroyed our family. If we could go back 17 years and change everything, we would. But we can’t. We need to put our family back together.”

As the 17th anniversary of the day Cassie disappeared approaches, just days before Thanksgiving, both Mary and Nate said this time of year is the hardest.

“The holidays haven’t been the same since,” Mary said. “I try to be strong for my other children. But this time of year is hard. I just hope and pray that we’ll find out who did this to my Cassie. We just need justice.”

Sgt. Reinbolt told Dateline that even though Cassie’s case has gone cold, they are still encouraging anyone who might know something or may have seen something from that time to call authorities.

If you or someone you know has information about Cassie’s case, call the Seneca County Sheriff’s Office at (419) 447-3456.