It's not such a happy Thanksgiving for one London family.

It was on October 13th, 1983 that 17-year-old Donna Jean Awcock was murdered.

The crime has never been solved.

On Sunday, family members gathered at Mount Pleasant Cemetery to mark the solemn occasion by releasing balloons in Donna Jean's memory.

Her killer has never been located and not having that chapter of this tragedy closed continues to impact the family..

"My dad never recovered from it, not at all. My dad passed away in 2004 not knowing who murdered his daughter," says Tammy Dennett, Donna's sister.

On the night of her disappearance Awcock was babysitting for a woman who asked her to make a run to the convenience store for her.

The clerk at the store said she remembered the young girl and says she looked nervous.

That was last time Awcock was seen alive.

Her body was found the next day near the Fanshawe Dam. She had been beaten, sexually assaulted and strangled to death.

Police have never been able to locate her killer but the hunt continues.

Recently, the reward for information leading to an arrest was increased to $50,000.

The family continues to hold out hope.

Each balloon released on Sunday holds information about Awcock's murder and contact numbers.

"My goal is to have it go to somebody who has some information," says Dennett.