The James R. Barker Lake Freighter lies trapped in ice near Whitefish Bay on Lake Superior April 7, 2015. The biggest ice cover on the Great Lakes in decades is backing up shipping traffic between the U.S. and Canada. Kenneth Armstrong / Reuters

The Barker is one of 10 ships that the Coast Guard is trying to free from the ice. Kenneth Armstrong / Reuters

A Canadian coast guard ship makes its way toward the stranded ships. Both the U.S. and Canadian coast guards are involved in the operation. Kenneth Armstrong / Reuters

A close-up of the Samuel Risley, one the the Canadian Coast Guard’s icebreakers. Kenneth Armstrong / Reuters

The ice can damage the brittle metal hulls of the freighter ships, many of which are decades old. Kenneth Armstrong / Reuters