Excerpts from nbcchicago.com:
Investigators haven’t been able to determine what caused an explosion at AB Specialty Silicones in Waukegan that killed four workers in May.
Waukegan Fire Marshal Steve Lanzi is confident investigators located the point of origin for the explosion and are ruling out intentional causes. He says the investigation was hampered because the workers who might have known what happened were killed in the blast that destroyed the factory.
He said that federal agencies and insurance company investigators are continuing separate reviews.
