The Chicago factory where workers staged a sit-in after they were abruptly laid off has filed for bankruptcy.

Republic Windows and Doors chief executive Richard Gillman made the announcement in a statement Monday.

The company said the bankruptcy filing for liquidation was a requirement of its creditor, Bank of America.

Gillman says what happened at his company is "a microcosm of what is happening to many large and small businesses."

A call seeking comment from the union representing the workers was not immediately returned.