Chicago (CBS) — Shortly before 10 a.m. Saturday, police received a call reporting a threat at the Elmhurst Library, which led to an emergency evacuation.

Following a lengthy search, police determined the building was safe.

But due to the nature of the investigation, police kept the library closed for the rest of the day.

Residents who were turned away from the library said senseless pranks like these are disappointing.

“I don’t think they really think of the consequences … and people’s lives get disrupted,” Elmhurst resident Pat McGowan said. “To see [the library] like this now, empty, it’s really unbelievable.”

In Illinois, swatting is no laughing matter. A 2016 law introduced harsher penalties and says that anyone found responsible must reimburse the agency for all reasonable costs of the emergency response, up to $10,000.

Elmhurst police said detectives are reviewing phone records and video to aid in the investigation.