A contractor performing maintenance aboard the tug Undaunted was hospitalized March 2 after the vessel’s carbon dioxide fire suppression system unexpectedly discharged while the boat was laid up in Ludington, Mich., authorities said.

The incident occurred about 11:30 a.m. while the tug was docked for the winter on Lake Michigan. According to the Ludington Police Department, a worker from a third-party vendor was conducting maintenance on the vessel’s fixed CO₂ fire suppression system when the system discharged, causing what officials described as a medical emergency.

Crew members and staff from Interlake Maritime Solutions, the tug’s owner, immediately began first aid and other potentially life-saving measures before emergency responders arrived, police said.

The injured worker was transported to Corewell Health Ludington Hospital by LIFE EMS, with assistance from the Ludington Fire Department. Authorities have not released the individual’s identity or condition.

The tug Undaunted is operated by Interlake Logistics Solutions, a division of Interlake Steamship Co., Middleburg Heights, Ohio which manages a fleet of bulk carriers operating on the Great Lakes. The vessel was in winter layup at the time of the incident.

Ludington police said the incident remains under investigation in coordination with Interlake Logistics Solutions. No additional injuries were reported.