CHESTER, ILL. — An explosion at a ConAgra Foods, Inc. mill in Chester on April 27 injured three contract workers. An investigation is ongoing into the cause of the explosion, which occurred inside a grain silo where cleaning crews were working.

On April 28, ConAgra said it had an investigative team on the ground at the mill, which employs 40, and is working with officials to try to determine the cause of the incident. No ConAgra Foods employees were hurt in the accident, and the condition of the contract workers that were injured has not been released.

The flour mill was not operating in the aftermath of the explosion, and the company did not know when operations would resume.

According to the Grain & Milling Annual 2009, the Chester mill has daily wheat flour capacity of 10,000 cwts and storage capacity of 1 million bus. ConAgra operates a second mill in Illinois at Alton, about 85 miles north of Chester. The Alton mill has 19,000 cwts of daily milling capacity.