By Walt Hunter

BRYN MAWR, Pa., (CBS) — Once again this May, the Mozino family quietly visited the Radnor Park where a tree, planted nearly 25 years ago, grows ever larger celebrating the life of 23-year-old Dawn Mozino, who vanished on May 22, 1989.

“I remember sitting on my porch, waiting for her to come up the hill,” Dawn’s mother Diane told CBS 3’s Walt Hunter.

“And then there was no Dawn and I remember the horrible panic of ‘where is she?’”

Waiting on busy Lancaster Avenue in the middle of Bryn Mawr for her bus, she was headed to practice for the Special Olympics she treasured.

“Special Olympics was her world,” Dawn’s sister Cathy told Hunter.

“She was so proud of her ribbons, her accomplishments, the friends she made.”

Then, suddenly, in the bright May sunshine, she was gone.

“It was just a pleasure to be around her on a day to day basis because she was always happy,” said her father Andrew, adding that Dawn’s sister Aubrey, now on the West Coast, has also been devastated by her disappearance.

“Everybody that met her loved her immediately,” explained her step mother Marian.”She was that kind of person.”

Beyond her family, Dawn’s disappearance haunts investigators including Radnor Police Sgt. Joe Maguire, the detective first assigned to her case.

“It never really leaves your mind,” Sgt. Maguire told Hunter. “Every time you drive that street you think about it.”

Lt. Andy Block says the Radnor Police Department is taking advantage of high-tech crime fighting tools like DNA analysis, hoping for leads in the case.

“We are passing it along to the next generation of investigators,” Lt. Block vowed.”We’re never going to forget about Dawn.”

Investigators think Thomas Hawkins, convicted for two other killings, and seen standing with Dawn that day, knows what happened. But as his execution draws ever closer, he refuses a standing offer to avoid the death penalty by telling whatever he might know about Dawn.

“Was she scared? Was she hurt? Did she cry out to anyone? Those are all the unanswered questions,” said Dawn’s sister Cathy.

Twenty-five years later the tree honoring Dawn reaches to the sky, blooming and beautiful, like the young woman this agonized family holds so close in their hearts.

“She’s with me every day in one way or another,” said Dawn’s mom.

“Her name is Dawn. You get up every day and it’s dawn.”

Family and friends will gather at 7 p.m. May 22nd to celebrate her life and, her family says, to hope and pray for answers to what of our regions oldest and most heartbreaking unsolved mysteries.