The exact cause of the Edmund Fitzgeraldās sinking is unknown. Traveling during a severe storm on Lake Superior, the freighter began listing before sinking on November 10, 1975. The Coast Guardās report concluded that due to improperly closed hatches, the ship took on water. With a loss of buoyancy, its bow dipped and was unable to recover, diving to the lake bottom. The suddenness explained the failure of the Fitzgerald to send a distress signal.
However, numerous other theories were promoted. Some believe that the freighter had struck bottom near Caribou Island, damaging its hull. Others, however, claim that the Fitzgerald was unseaworthyādue to structural problems, lack of watertight bulkheads, and cargo loads that were heavier than it was designed to carryāand that it broke apart while still on the lakeās surface. In addition, some have blamed rogue waves.