On December 27, 2019, an explosion occurred at the Indiana port steel plant of ArcelorMittal USA company, which resulted in the destruction of a converter and control room in the No. 4 steel production line of the steel plant. No.4 steel-making production line has been temporarily shut down, and the specific shutdown time has not been determined.

"Industrial water and molten iron in ArcelorMittal's Indiana port steel plant reacted violently, resulting in a fire that damaged the Indiana port 4 steelmaking line," said William Steeles, a spokesman for ArcelorMittal. The accident did not cause casualties. The company is very grateful for the hard work of the first rescue workers who arrived at the scene of the accident. They helped ensure the safety of the scene. "

"We are currently evaluating the specific time and downtime required to complete line 4 maintenance," stiles said. We will increase the output of other iron and steel plants and make full use of our inventory resources to offset the loss caused by the shutdown of production line 4. "

The Indiana port steel plant, east of Chicago, is the largest integrated long process steel plant in North America. It dates back to 1902 and was originally built by inland steel (now discontinued). The large-scale integrated steel plant used to employ more than 25000 workers to get raw materials from the lake by water, and its steel production once accounted for 5% of the national total.

In 2006, ArcelorMittal acquired Ispat international, whose Indiana port steel plant was renamed as the East Indiana port plant of ArcelorMittal. At present, the plant has about 4000 steel workers working in 3095 acres of steel-making facilities, mainly producing hot-rolled, cold-rolled, hot-dip galvanized and aluminized sheets.

In November 2019, Gary steel plant, an American steel company, had to suspend normal operation of a blast furnace due to a large-scale flood caused by pipe leakage. Several large steel mills in the northwest of Indiana have long been the economic pillar of the region and the center of the region's lifestyle. Most of them were built on the lakeside more than a century ago. With the difficult development of the domestic steel industry in the United States in recent years, the equipment of these steel mills is aging, and they are under considerable pressure in terms of maintenance and investment.