Today is the four year anniversary of the disappearance of Lauren Spierer, the Indiana University sophomore who went missing in 2011 after a night of partying.
Despite national attention and years of investigation, no arrests have been made in the case, and the cause of her disappearance remains unknown.
Lauren's mother Charlene posted a message to the family's Lauren Spierer Updates Facebook page this morning.
In it Charlene says their older daughter Rebecca was the first to learn of Lauren's disappearance. She describes being the parent of a missing child as "the nightmare you never wake up from."
"I trust that somehow, some day," she writes, "someone will be held accountable."
The post ends with a plea for information from anyone who might know what happened to Lauren, and a link to their website.
Here is the Facebook post in full:
Some Twitter users took to social media to mark the anniversary of Spierer's disappearance as well: