An anonymous voice mailer spurred the evacuation of a Mission District building Thursday, after she made multiple calls threatening to bomb the structure.

The saga actually began on Wednesday, police say, when a person bearing an "unknown female voice...left voice mails" for an undisclosed person or persons threatening to blow up a building on the 100 block of Fair Oaks Street, which is between 22nd and 23rd Streets.

That same caller was back at it as of 9:14 a.m. Thursday, leaving another voice mail threatening to destroy the structure.

This time, according to the San Francisco Police Department, officials "were immediately notified" and police "started the evacuation protocol" in the area to ensure all were safe.

And safe they were, as the voice mailer's threats were apparently empty. According to the SFPD, "a sweep by SFPD bomb dog yielded negative results for a bomb," and everyone was able to return to the area.

As of Friday morning, police say that no suspect information is available in the case, nor have any arrests have been made.