The dust has settled from a methane explosion last month that brought down the roof of a sludge concentration building at the Calumet water reclamation plant on Chicago’s far south side, but there is still uncertainty as to what triggered the blast.
The roof collapse injured 10 workers, one seriously. Carl Malinowski, 51, had worked in maintenance at the 96-year-old plant for more than a decade when he was called on Aug. 30 to perform the routine procedure of removing a frozen bolt with an acetylene torch.