For the last nine years, Crystal Soles has been missing, leaving behind anguished parents and a then 5-year-old son. Soles, 28, had called her father to say she was coming home, but she never did.
None of the searches ever turned up a clue as to where she might be. Soles was last seen outside a corner store in her hometown of Andrews, S.C.
"The pain is always there," her mother, Gail Soles, told ABCNews.com. "I just want to find my daughter and I am never going to quit."
Now, Soles watches empathetically as the families of missing Malaysia Airline's Flight 370 begin an unimaginable journey to find resolution. The Boeing 777 left Kuala Lumpur headed for Beijing 17 days ago and then seemingly vanished, fueling a nonstop array of theories from terrorism to a safe landing in a remote location.
What is Soles' advice to the 239 families of the missing passengers?
"Never give up my hope and faith," she said. "I think of my daughter every day."
But Soles, 60, warned that time never "softens" the grief.
Soles, a hardware store worker, is a good example of someone who has survived multiple losses. Just a year after her daughter vanished, her husband died. Seven months after that, her son was diagnosed with multiple sclerosis. Today, she is raising her daughter's son, who is now 14, and has two other grandchildren.
Soles was recognized by the CUE Missing Persons Center with the 2013 Passage Award as a "survivor that has healed and who has risen above to contribute one's self to those who remain in need of guidance, empowerment, support and who continually holds a devotion to the cause."
She attributes her survival skills to finding great support from others in that organization, which is this week holding its annual conference in Wilmington, N.C., "Breaking the Silence," which is hosting 350 family members of missing persons.
"They are my family," said Soles, who has attended every year since 2005 when her daughter disappeared. "I can tell them all my problems."
CUE founder and director Monica Caison said that survivors of this kind of trauma find support through others who have been through a similar experience. The conference "gives them empowerment and teaching tools to help them cope."
"They need to speak out their anguish and what they are going through," said Caison. "No, they don't move on. How can they when someone has disappeared from the family and circle of friends? It's very difficult. … They do not heal, they endure."
She said that because the fate of the passengers aboard Malaysia Airlines 370 was so uncertain, coping is all the more difficult.
"They are living in a state of unknown trauma," she said. "They don't even know if the plane has gone in the water for sure. They have a million thoughts: Did they make it? Did they land? Are they being held against their will?"
"You can't go through the process of grief because you are always in a state of trauma," she said. "You have to learn how to survive the trauma and when they are afforded a resolution, they can move on."
Those who can't move on feel guilt, anxiety, anger and "helplessness," according to Therese Rando, a psychologist at The Institute for the Study and Treatment of Loss in Rhode Island who worked with 9/11 families who lost loved ones.
"We need to see the body, to start the grieving process," she said. "What we know from research and clinical practice is that we need that to help start the road to moving on."
If there is no body, families of missing persons need "evidence" -- data or DNA -- "so they can look at the facts" and conclude that there was a death, according to Rando.
In the absence of facts, watching footage of the fall of the Twin Towers convinced some 9/11 families without firm evidence, that their loved ones were gone. Similarly, she said, after the war in Vietnam, when those "missing in action," were relabeled "killed in action," it gave some families permission to begin to live again.
But in a scenario like Flight 370, "without evidence and facts," mourning and eventual resolution are practically impossible, said Rando.
In not accepting a death, they ask, "What if my loved one is being held or mistreated? Should I contact one more authority? How will I celebrate the holidays?" she said. "They fight on because they can't confront the burden on themselves. How can I move forward and be happy?"
Families like those waiting for news of Flight 370 will need help "adapting to chronic uncertainty for the rest of their lives," said Rando.
"This presents the most difficult situation possible," she said. "You manage it, but you don't heal. And some do better than others.
People can only make it worse for these families by saying, "you are unwilling to accept reality," she said. "It's not their fault."