SUPERIOR, Wis. (AP) — Fraser Shipyards Inc. says it's working with a U.S. Occupational Safety and Health Administration investigation after a worker was burned last month.

The incident occurred Feb. 6 while the worker was servicing a vessel in the Duluth-Superior Harbor. The worker remains hospitalized in Duluth.

Fraser president James Farkas says the company reported the incident to OSHA and the International Brotherhood of Boilermakers and they are now working to understand what happened. The investigation involves a review of company policies, interviews and an on-site investigation.

Earlier this year, Fraser agreed to pay a $700,000 fine and make safety improvements in order to settle a case related to employee lead exposure, which happened during the repowering and refurbishing of the Herbert C. Jackson Great Lakes freighter.