She was last seen Oct. 6.

Fox News reports.

Mystery surrounds disappearance of Nevada college student Dianne Thacher

The disappearance of a college student in Santa Barbara, Calif., has police baffled and her East Coast family fearful Tuesday, after a full week of uncharacteristic silence.

Dianne Thacher, who at 23 was in her freshman year of study at Sierra Nevada College, in Incline, Nev., was last seen Oct. 6 checking out of a motel near Santa Barbara, where she was visiting friends. Days later, her family back home in Rhode Island, which is accustomed to hearing from her daily or seeing her new messages posted on Facebook, called police after realizing her phone had been turned off.

“It’s very strange she hasn’t communicated with anyone in a week — it’s unheard of,” said her older brother, Henry.

While police note they have no evidence of foul play, the Santa Barbara Sheriff’s Office and authorities in Washoe County, Nevada, are searching for the young woman and consider her disappearance suspicious.