US Steel says its largest mill is on limited production, after a shortage of vital iron ore due to the ice covering Lake Superior had temporarily shut down its furnaces.

US Steel had temporarily halted all steelmaking at its massive northwestern Indiana mill because the ice-covered Great Lakes have cut off the mill’s access to vital iron ore, stating in a letter to customers that it had idled the Gary Works complex’s blast furnaces and steelmaking due to “unprecedented ice conditions on the Great Lakes.”

However, on 7 April, company spokeswoman Courtney Boone said that ships were able to bring ore to the sprawling Gary Works on Sunday 6 April, despite lingering ice from the frigid winter. She would not specify the level of production or estimate the cost of the shutdown. She said US Steel hoped to get more ore to the mill in the course of the same week.

The mill, which feeds steel to big industries, was shut down for about a week.

A spokesman for the Great Lakes shipping industry says iron ore stockpiles are running low in many places and coal shipments are down 70% from a year ago.