(WPXI) — The Allegheny County Courthouse was evacuated “out of an abundance of caution” after a bomb threat Monday, Allegheny County Communications Director Amie Downs told our news partners at Channel 11. Downs said an anonymous call came in Monday morning that there was a bomb inside the courthouse. About 250 people were forced to evacuate. Allegheny County Sheriff Kevin Kraus said about half a dozen bomb-sniffing K9s were brought in to inspect the building. They did not find anything and after about 90 minutes investigating, authorities deemed the building safe. Employees were then allowed to file back inside followed by community members with appointments and scheduled court appearances. Sheriffs office detectives are now trying to figure out who called in the bomb threat. When they do, they say that person will face charges.