MATTAWA, Wash. -

A senior at Wahluke High School is accused of reporting a false threat last Thursday to the school in Mattawa.

The Grant County sheriff's office says the 18-year-old girl was arrested Tuesday and jailed for investigation of making threats.

She called dispatchers and said she had received a private Facebook message that someone was going to shoot up the school. She refused to identify herself. A search warrant enabled investigators to access her Facebook account, which showed no threatening message.

She has been expelled from school