An explosion has occurred in a slag pit in northwestern Indiana.
The blast at Lafarge North America in East Chicago Sunday afternoon was at a contractor's facility at a mill that turns slag into cement, the (Northwest Indiana) Times reported.
No injuries were reported, said Patricia Persico, a spokeswoman for Cleveland-Cliffs Indiana Harbor West.
The explosion was in the raw materials section of the mill along Lake Michigan. Several small fires at the mill had to be extinguished.
Slag is a highly volatile byproduct of steelmaking prone to exploding when mixed with water, according to the newspaper.
Persico said recent rain caused the explosion.