(NewsNation) — When a person goes missing, their loved ones are left with the agonizing void of having something ripped away from them. Imagine the emotions involved if it was two young sisters who vanished at the same time.

That’s what authorities say happened 21 years ago to a Chicago family. Tionda and Diamond Bradley, two little girls, disappeared in 2001.

Despite the roller coaster of emotions, false sightings and hoaxes by people claiming to be their long-lost loved ones, the family isn’t giving up hope.

Two decades after the disappearance, Sheila Bradley-Smith is still monitoring tips for any information about her great-nieces. The girls were ages 10 and 3 when they vanished.

Time barely dulls the grief.

“What people don’t understand is … it’s been 21 years. But to us, we’re stuck in 2001,” Bradley-Smith said.

Tionda and Diamond’s mother left their Chicago apartment with her boyfriend in the early hours of July 6, 2001. When she returned home from work at around 11 a.m. the girls were gone.

A note said the girls had gone to the store and the park, but family members say the note seemed “off.”

“For one, Tionda would not have written a note. Tionda would have called her mom’s cellphone,” Bradley-Smith said.

A massive police investigation followed by air, from the water and along railroad tracks. K-9 search teams went through empty lots and more than 5,000 abandoned buildings, scouring the area for the girls.

“It was the largest manhunt in Chicago police history,” Detective Ed Carroll said. “The department threw all the resources they had at the investigation because of the age of the children.”

Bradley-Smith questions who would have known that the girls were home alone at the time.

Investigators on the case did find evidence, including a hair matching Tionda’s, in the trunk of a car, but nothing conclusive enough to make an arrest.

“There was a couple of people we were focused on in, in my part of the investigation,” Carroll said. “Unfortunately, we were never able to make anything stick, anything that we could go to a state’s attorneys with.”

Through the years, several people have come forward claiming to be the missing girls, including a Texas woman on Facebook in 2019 who started texting the family. They became suspicious when the texts turned aggressive, then the woman stopped responding. The FBI determined she was not Tionda.

“It’s still a letdown,” Bradley-Smith said. “It’s always a letdown.”

The family holds a vigil every year, making sure the case of Tionda and Diamond is not forgotten.

“Just because it’s a cold case, it shouldn’t be a forgotten case,” Bradley-Smith said.

Chicago police say the case is still an open investigation, but there are no new leads at this time.

Just last week, another person reached out to Bradley-Smith saying she was adopted years ago by her older sister, and believes she could be Diamond. The family put her in touch with police to see if there could be any connection. However, after the number of times this has happened over the years, Bradley-Smith says family members are not holding their breath.