ST. LOUIS (AP) — Peabody Energy Corp.’s plans to close a 400-worker Illinois coal mine marks another “heartbreaking” hit for a struggling region still mending from a deadly tornado last year and another coal producer’s intent to shed dozens of jobs, a top administrator said Wednesday.

St. Louis-based Peabody announced this week that one of its subsidiaries, Big Ridge Inc., will permanently shutter its Willow Lake Mine near Equality in Saline County. It said the operation was “unsustainable” due to the mine’s failure to meet acceptable standards for safety, compliance and performance.