CHICAGO (SUN TIMES MEDIA WIRE) - Investigators have revealed the cause of the explosion that injured 10 people and caused a building collapse Thursday morning at a water treatment plant in the Far South Side Riverdale neighborhood.
The city’s Office of Fire Investigations determined the explosion was caused by the use of a torch in an “area with significant amount of methane gas present,” according to Fire Media Affairs. The torch ignited the gas, causing a shock wave that lifted the roof.
The explosion happened shortly before 11 a.m. at the plant at 400 E. 130th St., according to Chicago Fire Department spokesman Larry Merritt.
The explosion caused the roof of the Calumet Water Reclamation plant’s sludge concentration building to collapse, according to Metropolitan Water Reclamation District of Greater Chicago spokeswoman Allison Fore.
As of Friday afternoon, eight of the workers who were hurt had been treated and released from hospitals, according to Fore. None of the others hurt had injuries that appeared to be life-threatening.
Two patients were brought to Christ Medical Center in Oak Lawn, Merritt said. A spokeswoman for University of Chicago Medical Center said four other patients were brought in for treatment. By Friday morning, one of them remained in serious condition, another remained in fair condition and the two others had been released.
The hospital and conditions of the four other workers who were hurt was not immediately known.
Fore said the explosion has not interfered with the plant’s water treatment operations.
“Our staff have worked diligently to ensure treatment operations continued to function as designed,” she said in a statement. “There is no threat to the public and we will continue to treat water at the plant as normal.”