On March 28, 2024, at about 12:18 am, the American Mariner was traveling up the St. Marys River about 25 miles south of Sault Ste. Marie, Michigan, when a steering failure caused the bulk carrier to strike the Munuscong Channel Junction Light, a 31-foot-diameter cylindrical fixed concrete structure with a giant light on top. The vessel took on water, but the crew stabilized it using pumps, and none of the 18 aboard were injured. Still, the American Mariner sustained more than $800,000 in damage, and the light suffered an estimated $1.25 million in damage.