November 10 marked the 50th anniversary of one of the Great Lakes‘ most famous and mysterious shipwrecks – the sinking of the SS Edmund Fitzgerald on Lake Superior in 1975.

The loss of the freighter and all 29 crew members shook the country. No freighter had been lost on Lake Superior since 1953, and the Fitzgerald was outfitted with an experienced crew and state-of-the-art technology. Inexplicably, the ship hadn’t launched any lifeboats or transmitted a distress signal to nearby ships.

When it first went into service in 1958, the Fitzgerald was the largest ship on the Great Lakes and the most expensive ever built at a cost of $8.4 million. With its ability to haul more than 25,000 tons of cargo, the Fitzgerald set to work hauling taconite across the lakes, frequently bringing iron ore from Silver Bay, Minnesota, to steel mills near Detroit and Toledo.

On November 9, 1975, the Fitzgerald was headed from Superior, Wisconsin, to Great Lakes Steel near Detroit with a winter storm building.

The Fitzgerald and a nearby ship, the Arthur M. Anderson, stayed in close radio contact as they traveled, agreeing to take a northerly route across Lake Superior where they’d be more protected by highlands on the Canadian shore.

But soon winds reached near-hurricane strength at 65 to 70 mph, with gusts up to 100 mph.

In the afternoon, on November 10, Captain Ernest McSorley reported some damage, including a fence rail down and the loss of its radar, and asked the Anderson to guide him to Whitefish Bay, Michigan. At 7:10 p.m., the Anderson’s captain, Bernie Cooper, checked in to ask how the Fitzgerald was doing, and McSorley reported, “We are holding our own.”

Those would be the last words heard from anyone on the Fitzgerald. A few minutes later, the ship disappeared from the Anderson’s radar and never reappeared. When Captain Cooper radioed around 7:22 p.m., there was no answer.

The ship was eventually found in two pieces beneath 530 feet of water about 17 miles from the entrance to Whitefish Bay.

Even 50 years later, the reason for the ship’s demise is still in debate.

In 1977, a Coast Guard study found that the cause couldn’t be conclusively determined, but it named massive flooding in the cargo hold, due to the crew’s failure to properly close hatches, as the most likely cause.

However, others, including Cooper, disagreed with the Coast Guard and argued that the Fitzgerald had passed too close to a shoal during the storm, damaging the ship enough to sink it.

Lauren Peck was media relations / social media associate at Minnesota Historical Society. This article first appeared in the November 2015 issue of Minnesota Good Age. Updates have been made to make it more timely.