CHICAGO (Reuters) - A powerful explosion at a manufacturing plant in a Chicago suburb on Tuesday killed one worker and injured 12 people, including some who breathed in a caustic chemical released by the blast, the local fire chief said.
A 55-year-old employee was repairing a testing machine at Arens Controls, a maker of electronic parts for automobiles and other vehicles, when there was an explosion in the machine, killing him, Arlington Heights Fire Chief Glenn Ericksen said.
Seven workers among the 50 others working at the plant suffered concussion-like injuries, Ericksen said.
The explosion was so powerful it buckled the plant's ceiling 20 feet above and knocked stones off the roof, damaging cars parked nearby, he said.
Three police officers and two firefighters who evacuated the injured suffered breathing problems from residual fumes from the release of potassium hydroxide, a chemical that can cause respiratory distress similar to a drain cleaner, he said.
The plant is in an industrial area of Arlington Heights, a suburb northwest of Chicago.
The cause of the explosion was not immediately known, but a preliminary investigation indicated it was an accident, Ericksen said. Investigators from the Occupational Safety and Health Administration will look into the incident, he said.
(Reporting By Andrew Stern; editing by Cynthia Johnston and Mohammad Zargham)