Schiller Park bakery in Chicago will close its doors Oct. 19 after 84 years in business making the iconic snack.
Twinkies were invented in 1930 in Chicago and Schiller Park bakery was the last facility in Illinois that still made the treat.
Donald Woods, president of the Bakery, Confectionary, Tobacco Workers and Grain Millers International Union Local 1, said he and fellow union members were shocked at the news.
"It's devastating for them," he added.
The company is offering a severance package to the some 400 employees affected by the closure.
The entire company and all production of snacks were temporarily shut down in 2013 after Hostess Brands filed for bankruptcy. The brand was purchased for $410 million by private equity firms Apollo Global Management and C. Dean Metropoulos & Co. and reopened last year.
The facility is being closed in an attempt to turn around the company, CEO Bill Toler said.