SPRINGFIELD, Ohio (AP) — A manufacturing plant worker who sent her sister a text about an active shooter as an April Fools’ Day joke was arrested after her frightened sister notified authorities about the apparent threat, spurring an immediate law enforcement response.

Pamela Sisco, 57, of New Carlisle, was charged with inducing panic and disrupting public services. She also was suspended from her job at the Navistar plant in Springfield.

WHIO reported that Sisco texted her sister late Thursday morning that a man who had been fired from the plant the day before had returned with a gun and the workers were hiding in locked offices. Sisco’s sister then called authorities to report the incident, telling a dispatcher she was afraid to text her sister back if they were hiding, the Clark County Sheriff’s Office said.

Numerous police agencies immediately responded to the plant around 11:45 a.m. and soon found Sisco, who admitted she had sent the text to her sister as an April Fools’ Day joke. Officers found no threat of any kind inside the plant.

It wasn’t known Friday if Sisco has retained an attorney.