Executive Summary
About 2010 local time on February 16, 2019, a fire was reported on the bulk carrier St. Clair while the vessel was laid-up for the winter at the CSX TORCO Iron Ore Terminal (TORCO dock) at the mouth of the Maumee River in Toledo, Ohio. No one was on board. The fire was extinguished approximately 36 hours later by shoreside firefighters. No pollution or injuries were reported. The estimated property damage exceeded $150 million.
Probable Cause
The National Transportation Safety Board determines that the probable cause of the fire aboard the bulk carrier St. Clair was the ignition of combustible material in the vicinity of an engine room workshop likely due to the use of portable space heaters or smoldering smoking materials, which spread to other areas of the vessel. Contributing to the extent of the fire damage was the lack of operating procedures for continuous active monitoring of the vessel while in layup status.
Full report here: https://www.ntsb.gov/investigations/AccidentReports/Reports/MAB2015.pdf