Even the falling drizzle couldn’t dampen the soaring spirits of the crowd who gathered on the banks of the Chicago River on July 24, 1915. Employees of the Western Electric Company, the country’s only telephone manufacturer, savored a rare Saturday off and looked forward to a day of fun with family and friends at the company’s annual summer excursion to Michigan City, Indiana. Not wanting to miss a single enjoyable moment, passengers with picnic baskets and baby carriages in tow began to board SS Eastland, the first of five vessels chartered by Western Electric, at the early hour of 6:30 a.m.

Women in long summer dresses and men in three-piece suits chuckled and joked as the slender steamship occasionally rocked from side to side during the hour-long boarding in what felt like a preview of the roller coaster and other stomach-dipping amusements that awaited them on the other side of Lake Michigan. Deep below deck, however, Eastland’s crew knew the listing was no laughing matter. “The Speed Queen of the Lakes” may have been one of the Midwest’s fleetest ships, but it was hardly the safest. The ballast system, which was designed to keep the steamer on an even keel, suffered from repeated malfunctions, and at least twice before—in 1904 and 1907—the vessel nearly capsized. “Eastland’s owners were aware of stability problems that needed to be repaired but planned to postpone them until after the sailing season ended in 1915 because of the expense,” says Michael McCarthy, author of “Ashes Under Water: The SS Eastland and the Shipwreck That Shook America.”

The required addition of lifeboats on the top deck in the wake of the 1912 sinking of Titanic and a recent 500-passenger capacity increase authorized by inspectors only compounded the steamship’s stability problems. With its three decks packed to its new 2,500-person limit, Eastland began to creep away from its berth at 7:30 a.m., but as its stern swung into the Chicago River, the ship’s listing from side to side turned violent.

“Look out, she’s tipping!” cried warehouse workers along the river. Dishes and bottles crashed to the floor. Panic along with the Chicago River gushing through gangways and portholes swept across the decks. Frightened passengers and crew jumped to the dock as the last line holding Eastland to the wharf snapped like a whip.

For those on board the steamer, the world suddenly turned sideways.

Eastland rolled onto its port side and rested partially submerged in less than 20 feet of water. “It lay like a toy boat of tin wrecked in a gutter,” reported the Chicago Tribune. The unfortunate passengers who happened to be on the port side were crushed by the hundreds of people, deck chairs and other furniture that suddenly fell on top of them. “The entire crowd of men, women and children came slipping and sliding and sprawling down with a mass of lunch boxes, milk bottles, chairs—rubbish of every sort—on top of them,” said passenger George Goyette. “They came down in a floundering, screaming mass.” As the enclosed decks filled with water and debris, the mob of humanity who tried to scale the staircase to the promenade deck, now turned sideways, turned the lone escape path into a deathtrap.

Screams mixed with gurgles as survivors struggled to stay afloat in the filthy river, a toxic cocktail of raw sewage and detritus from Chicago’s stockyards. Few passengers knew how to swim, and even those who did were weighed down by their water-logged dresses and heavy suits. Rescue boats scrambled to the scene as welders ran with torches in hand to the crippled steamer. Hearing the muffled cries of the desperate passengers pounding on the metal hull, the welders began to cut rectangular escape hatches when Eastland’s horrified captain, Harry Pedersen, incredibly protested that they were “ruining his ship.” “The captain showed more regard for the company property than the people inside,” McCarthy says.

As doctors tried to force water out of victims’ lungs with pulmotors, rescue workers hoisted lifeless bodies found by divers working in the dark holds of the ship. In all, the Eastland tragedy claimed 844 victims, including more than 50 infants. In just mere minutes, the capsizing wiped out 22 entire families.

Pedersen, the ship’s engineer and four of its owners stood trial for the disaster, but a federal judge changed the original charges from criminal negligence and manslaughter to conspiracy to operate an unsafe ship. As McCarthy notes, the owners may have been negligent, but there certainly was no conspiracy. Represented by the legendary Clarence Darrow—who was in the “valley of his career” according to McCarthy after accusations of bribing jurors on an earlier case—the six men were all found not guilty. No one was ever held criminally responsible for the disaster, and a civil trial that dragged on for more than two decades ultimately provided little money to victims’ families. “I don’t believe justice was done,” McCarthy says. “The Eastland story offers an example of how important it is to bring charges against people who have endangered lives and how careful you must be to pin the charges on them.”

Although the Eastland disaster was the deadliest in Windy City history—claiming seven times the lives as the official death toll from the Great Chicago Fire—it quickly faded from public memory. McCarthy attributes this in part to the lower economic status of the victims as well as the timing. “This happened just before the U.S. entered World War I, and the world-changing events eclipsed so much else of what was going on,” he says while adding, “It is remarkable that something so catastrophic wouldn’t be better remembered.”