"This is hardest thing not knowing where your child is, where your grandchild is whether they are alive or not," said La Shann Walker.
LA SHANN WALKER: We're still looking and searching. I'm not giving up.
EVELYN HOLMES: It's another desperate plea for help, as La Shann Walker vows to never stop searching for her missing daughter and grandson. Diamond Bynum and King Walker went missing in 2015.
LA SHANN WALKER: This is the hardest thing, not knowing where your child is, not knowing where your grandchild is, whether they are alive or not.
EVELYN HOLMES: This afternoon outside the Gary Police Department, Walker clings to her belief that the pair are still alive somewhere. Meanwhile, Walker's supporters say the case has gone cold because detectives no longer return her phone calls. The Gary Police Department did not return calls or emails for comment.
MICHAEL BEN-YOSEF: The sense of urgency has gone beyond the recognition of what needs to be done.
EVELYN HOLMES: Diamond Bynum and King Walker disappeared nearly six years ago while visiting a relative's home in Gary, Indiana. Bynum, who is developmentally disabled, was 21 at the time. Her toddler nephew just turned tow. Diamond's 27th birthday was Thursday.
KATHY CLEMENT: Somebody out there knows something. Why they have not come forward is beyond me.
EVELYN HOLMES: The family celebrated after the National Center for Missing and Exploited Children shared an age progression image of how King may look now. So far, that's generated few leads.
The family says they have asked for Gary's mayor to get involved to help move this case along. They say if that doesn't work, they will go to state and federal officials to get help as they continue to look for their missing loved ones.
Reporting from the Gary Police Department, Evelyn Holmes, ABC7 Eyewitness News.