CHICAGO (AP) — State labor officials are investigating an Illinois-based pharmaceutical company’s decision to abruptly close all of its operations, including its out-of-state locations in New Jersey, New York and Switzerland, and to lay off hundreds of workers with almost no warning.

Akorn Operating Co., which is based in the northeastern Illinois city of Gurnee, told its 400 workers Wednesday that it planned to file for bankruptcy and that they would be laid off within 24 hours, the Chicago Tribune reported.

CEO Douglas Boothe told employees in a video that the company’s leaders decided on the move after failing to find a buyer for the company.

“I realize this is a tremendous shock and it will take time to absorb the news and what it means to you, your colleagues and your families,” Boothe said in the video, which was first obtained by the Decatur Herald & Review.

A spokesperson for the Illinois Department of Labor said Thursday that the agency is investigating the situation because Akorn didn’t file the required 60-day notice of mass layoffs or plant closures until Wednesday.

Boothe said in his video that the company notified the U.S. Food and Drug Administration of the closure. The Tribune’s attempts to reach the company Thursday for additional comment were unsuccessful.

Akorn’s Illinois locations include its corporate headquarters in Gurnee as well as manufacturing and research facilities in the Chicago suburb of Vernon Hills and in Decatur, in central Illinois. The company also has locations in New Jersey, New York and Switzerland.

The company developed, manufactured and marketed a wide array of branded and generic prescription drugs, including eye drops, injectables, oral liquids, inhalants and nasal sprays, according to its website. It also developed drugs for animals.

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