​​​​​​​​​​This information is preliminary and subject to change.

​​​On March 28, 2024, about 0030 local time (eastern daylight time), the 714.8-foot-long US-flagged cargo vessel American Mariner experienced a mechanical failure, and the vessel struck the Munuscong Channel Junction Light ​​(a roughly 15-by-15-foot concrete navigation aid with a buoy on top) in Munuscong Lake, Michigan, about 25 miles south-southeast of Sault Ste. Marie, Michigan. The vessel began taking on water in the forepeak and no. 1 port hold. Pumps were able to keep up with the flooding. After completing inspections and receiving an approved transit plan, the vessel transited to a repair facility in Ashtabula, Ohio. No pollution or injuries were reported. Initial damage assessments exceeded $500,000.​​

The US Coast Guard has declared this incident a major marine casualty. The Coast Guard will lead the investigation, and the NTSB will investigate and determine the probable cause.