The General Slocum was built in Brooklyn in 1891, a 235-foot sidewheel steamer with a legal capacity of 2,500 passengers. Named for Civil War general and New York Congressman Henry Warner Slocum, she was owned by the Knickerbocker Steamboat Company. Each of her massive paddle wheels carried 26 paddles, churning through the waters of Long Island Sound and the East River on chartered excursion runs. But behind the festive paint and brass fittings, the vessel carried a grim secret: years of deferred maintenance had left her fire safety equipment in shambles. Life preservers had rotted from age, crumbling to dust when passengers desperately strapped them on. Fire hoses were brittle and useless. The crew of 22 had never conducted a proper fire drill. The General Slocum was, by every measure, a disaster waiting to happen.

The fire broke out in a storage compartment near the bow as the steamboat moved up the East River, likely ignited by a discarded match or cigarette near barrels of hay and oily rags. Captain William H. Van Schaick, a veteran mariner, faced an impossible choice: beach the burning vessel at nearby shoreline docks, risking the spread of fire to oil storage facilities and lumber yards, or press on toward North Brother Island. He chose to keep steaming ahead, and the wind whipped the flames into an inferno. Passengers rushed to the stern as fire consumed the wooden decks. The rotted life preservers disintegrated or, worse, were filled with cheap cork dust weighted with iron bars, dragging wearers beneath the surface. Most of the women and children had never learned to swim, as was common in the era. The heavy, layered clothing of the day became waterlogged anchors. Within thirteen minutes, the General Slocum was a burning hulk beached on the shallows off North Brother Island.

While the captain and several crew members abandoned ship by jumping onto a nearby tugboat, extraordinary acts of courage unfolded around the wreck. Staff and patients from the hospital on North Brother Island rushed to the shoreline, forming human chains that stretched into the water to pull victims to safety. Construction workers repairing the hospital building carried their ladders to the riverbank and extended them toward drowning passengers. Two tugboats arrived within minutes and are credited with saving between 200 and 350 people. Of the 1,342 people aboard, only 431 survived. The dead included two of the vessel's 30 crew members. An estimated 400 to 600 people drowned after the ship was beached, jumping from the stern into deep water, while those who leapt from the bow found shallower water and a better chance of survival.

The General Slocum disaster did not merely claim over a thousand lives; it destroyed an entire community. Manhattan's Little Germany, a vibrant neighborhood centered around Tompkins Square Park on the Lower East Side, was devastated. Nearly every family in the tight-knit German-American enclave lost a mother, a child, a sister, a cousin. The grief was so overwhelming, the reminders so inescapable, that within a few years the surviving families simply left, scattering to Yorkville, Brooklyn, and Queens. Little Germany ceased to exist as a distinct neighborhood, one of the most complete destructions of an urban community in American history. The disaster held the grim record as New York's deadliest manmade catastrophe until the September 11 attacks in 2001. Captain Van Schaick, who lost sight in one eye from the fire, was the only person criminally convicted. Sentenced to ten years in prison, he was pardoned by President Taft in 1912.

Today, a small pink marble monument in Tompkins Square Park stands as the primary memorial to the General Slocum victims. Each June, a handful of descendants and history enthusiasts gather there to lay a wreath. At the Evergreens Cemetery in Brooklyn and the Lutheran Cemetery in Queens, mass graves hold hundreds of unidentified victims. The disaster led directly to sweeping reforms in steamboat safety regulations and federal inspection standards, changes that came too late for the families of Little Germany. The General Slocum herself was raised, stripped to her hull, renamed the Maryland, and converted into a barge. She sank for a second and final time off the coast of New Jersey in December 1911, her remains resting on the ocean floor as a footnote to one of America's most devastating and least remembered tragedies.