The explosion Sunday in a raw materials section of the sprawling Cleveland-Cliffs Indiana Harbor West mill on the Lake Michigan shoreline “was caused by rainwater meeting the hot slag.”

The Environmental Protection Agency hopes states like Indiana will use new greenhouse gas inventory tools to reduce their emissions.

Indiana releases the most toxic pollution per square mile and the state's top three emitters are steel companies.

The state of Indiana announced Wednesday that Alliance Steel plans to invest $19.7 million in Gary, about 25 miles from its plant in Bedford Park, Illinois.

Details weren't announced pending ratification meetings, which are expected take place in coming weeks. But the union says the deal includes only some of the company's Indiana workers.

Steelworkers say they're not benefiting from the industry's rising prices and profits, brought on partly by the Trump administration's tariffs on steel imports.

Company and government officials say the project will help preserve Gary Works' nearly 3,900 steelworker jobs and could help ensure the 112-year-old mill lasts another century.

A state analysis of local wind patterns suggest that the lead released by the mill complex could be blowing north and west toward Chicago or south toward the Indiana community of Chesterton.

Raw steel production in Indiana rose by 1.2 million tons last year to 24.4 million tons.

The three-year project will focus on how to add larger amounts of silicon, which helps conserve energy, to the small steel components of electric motors.