NORMAL - Joe Kingdon can remember working on a landscaping project three years ago with his friend he'd had since the third grade - Tristan Warner.
"It wasn't really his thing," Kingdon said. "But thinking back on it, we had a lot of fun."
On Sunday, Kingdon spent the morning helping Warner's family and friends landscape around the memorial sign that was erected for his friend outside Normal Community High School in 2004.
Warner was a senior in high school, who had dreamed of attending the University of Arizona since he was a child. He found out he had mononucleosis around the same time he got his acceptance letter.
"How many kids get mono over the course of a year in high school? The thought (of him dying) never even crossed our minds," said Tristan's mom, Annette Warner.
But Tristan Warner died on Christmas Eve, almost two months after his diagnosis.
"It was tough," said Annette Warner. "It's not what we had envisioned for our 17-year-old son."
She said doctors are still unsure exactly what caused his death. He was tested for cancer numerous times and other diseases, but it has remained a mystery.
"They're (doctors) still testing his DNA for a rare disease," said Warner. "But if the test comes back negative, they don't know what else it could be."
She said the family, which includes husband, Barry and son, Cameron, a junior at University High School, would never have made it without the support of family members and friends.
"We couldn't do it without them," said Warner. "We wouldn't be anywhere without our faith, our family and our friends."
She said Tristan's death has affected each of them differently.
"I think Cam has realized just how precious life really is," said Warner. "He's made some wise decisions because he sees that."
Cameron Warner said working with family and friends to lay rock around the memorial sign reminds him of Tristan waking up early on mornings in the summer to go work at Ironwood Golf Course.
"I guess it just shows how he made an impact on peoples' lives," he said. "That they would all come together to help out like this."
Nina Frank, like Kingdon, is a sophomore at Illinois State University. She said she first saw Tristan in the hallway early on in high school.
"I always thought he was 'the cute boy,'" she said. "I stalked him for a good half a year before we actually started talking."
Frank said the two were dating when he died.
"It was the funny, stupid, not so smart things he did that made people love him," she said. "The crazy things he did made us all love him. And you can't forget things like that - you can't."