More than 100 people are considered missing after last weekend's devastating landslide near Oso, Washington. That number continues to fluctuate.
Experts say it's often difficult for authorities to figure out how many people are unaccounted for in the immediate aftermath of a natural disaster.
In a plane crash, there's usually a known number of people on board. In a catastrophe like the Snohomish County landslide, it's impossible to know how many people were affected. Some homeowners were likely out of town. Some may have had house guests. Some people were simply driving through the area and got caught up.
The Oregon Office of Emergency Management's Kim Lippert says that uncertainty is common with any natural disaster. Some people are counted twice.
Lippert adds, "Often when people are actually safe they may be so overwhelmed by the trauma of the situation that they may reunite with their families but not circle back with authorities to let them know that they are okay."
Lippert says once the initial shock has worn off, people who think they might be considered missing should contact emergency management officials. That will help make sure rescuers aren't looking for someone who is actually safe.
To report a missing or a located person, called the Snohomish County Department of Emergency Management at 425-388-5088.