It has been more than a week since Malaysia Airlines Flight 370 disappeared, and despite a massive search effort, the whereabouts of the plane and the 239 people on board are unknown.
The airline has told the families and friends of those missing to "expect the worst."
But it's tough for families to grieve without knowing the answer to a crucial question: Could my loved one still be alive?
Dr. Pauline Boss works with people in this kind of situation. She's the author of Loss, Trauma and Resilience and a professor emeritus at the University of Minnesota.