A steelworker’s June death, which was initially thought to be from a heart attack, remains under investigation as an accidental electrocution. According to a report from NWI.com in Indiana, Valparaiso resident Charles Kremke, 67, died in a hospital after his accident in the U.S. Steel Gary Works mill during the day shift on June 15.

The integrated steel mill sits on the shore of Lake Michigan. Another steelworker, Jonathan Arizzola, a 30-year-old Valparaiso resident, died in a crane accident on Sept. 30 at Gary Works. His wife said he suffered an electrical shock in a separate accident earlier that week, nwi.com reported.

Kremke’s death was initially believed to be the result of a heart attack. The coroner said the preliminary manner of death was in fact an accident and the cause was electrocution.

Both deaths are still under investigation.