A Kentucky mom who volunteered with an organization dedicated to searching for missing persons has herself vanished, police said.

Andrea Michelle Knabel, 37, was last seen on foot near Audobon Park after leaving a relative’s home around 1 a.m. Aug. 13, according to the Louisville Metro Police Department.

The single mom of two contacted a friend around 1:30 a.m. to ask for a ride, but calls to her phone have since gone to voicemail, the Louisville Courier-Journal reported.

Police are searching the city and surrounding areas for Knabel, who was a volunteer with Missing in America, a national group that works to locate missing persons, the outlet reported.

“Keep your eyes open,” private investigator Dan Washington told the newspaper. “Anything, even the smallest minute detail, could unravel the whole thing and lead us to the right direction. So continue to share and continue to keep your eyes open.”