DALLAS (CBSDFW.COM) – Dallas police evacuated the Fountain Place office building at 1445 Ross Ave. and blocked off surrounding city streets after an employee made a joke bomb threat Saturday morning.

At about 6:45 a.m. Saturday, Fountain Place security called police after finding a “threatening” note attached to a scooter that was parked in the underground garage.

The note said the scooter was rigged to explode if the building’s computers were not unplugged, DPD spokesman Sgt. Warren Mitchell said.

Police and the building’s management then had the building evacuated, while DPD blocked off surrounding streets.

“Officers are uncertain if the threats are real, but are taking every precaution until they can determine otherwise,” Mitchell said at the time.

After a brief investigation, police found that “the manager of a restaurant located inside the office building left the note on the shift manager’s scooter last night to remind her to unplug the computers because of a power shutdown that was to occur later in the day,” Mitchell said.

No charges were filed initially, though a false alarm or report offense was made. Police questioned three employees and released them Saturday afternoon. The manager who left the note could still be charged.