SOUTH HAVEN, Mich. -- This week will mark the 100th anniversary of a shipwreck disaster many historians will tell you was the worst in the history of the Great Lakes area. The sinking of the S.S. Eastland, a catastrophic event, took place in 1915. The Eastland rolled over on its side just feet away from the boardwalk at which it was docked, killing 844 people.

“The Eastland is known throughout the world as the worst Great Lakes disaster,” said Valeria Van Heest of the Michigan Shipwreck Association and author of "Lost and Found: Legendary Lake Michigan Shipwrecks."

The Eastland had ties to West Michigan. The vessel acted as an excursion boat from Chicago to the beaches of West Michigan and made regular trips to South Haven.

But on the fateful day in 1915, the Eastland had a different route planned. That day, the ship was bound for Michigan City, Indiana, with nearly 2,000 employees of the Western Electric Company for a company picnic.

“Those tickets were a mere dollar to get them to Michigan City for a day of picnicking and enjoyment,” said Van Heest, “and instead ended in tragedy.”

It was a rainy day, so most passengers headed below deck to escape the elements, a mistake that would prove fatal for many. Around 7:15 a.m., as the boat finished boarding and prepared to set sail, it inexplicably capsized and filled with water, just feet away from the dock.

Many passengers were killed on the initial capsize, hit by furniture or other projectiles. Many others, dressed in customary travel garb that included long dresses and three-piece suits, drowned in their heavy clothing as the ship quickly filled with water.

Van Heest and many other historians believe the design of the ship was to blame.

“Long, slender, but top-heavy,” Van Heest said, describing the design of the Eastland. “That probably explains why it was sold five times in 12 years.”

Because it happened so close to dry land, the Eastland disaster is one of the most photographed in shipwreck history. But there was no film footage -- until very recently. And it was discovered completely by accident.

A University of Illinois graduate student poring over World War I footage stumbled upon what shipwreck historians had thought didn't exist: footage of the Eastland incident.

That set off a firestorm of searching for anything else that may have existed. And not long after, anothe lucky find by a professor with the Northern Illinois University who discovered more footage, again by accident.

“This piece of footage was much different,” said Van Heest.

Whereas the original footage showed only rescuers working on the ship, the second piece of footage showed bodies being drawn from the vessel. It was a grim look at this historic event most, like Van Heest, thought they’d never see in moving images. Grim, but important.

“There’s something about moving footage that makes an accident like this more real,” she said. “We can read about things, we can look at pictures, but moving footage says it all. And what a tragedy this was 100 years ago, so close to where we are now.”

It took crews three weeks before they finally finished removing all the bodies from the water and were able to upright the Eastland.

Eventually, the ship was sold to the Navy, pending a few modifications, as a commissioned vessel.