In 1969, the U.S. Army Corps of Engineers temporarily stopped the flow of water over the American side of Niagara Falls to study erosion, uncovering chilling secrets beneath the dry riverbed. Among their discoveries were human remains—a man and a woman whose identities and stories remain unknown. The woman’s body was found first, and the man’s was discovered the next day, reportedly after he had leapt into the falls.

Engineers also found millions of coins tossed into the falls by visitors, revealing hidden mementos beneath the waters. The project, which lasted about six months, redirected water entirely to Horseshoe Falls on the Canadian side. This effort helped researchers understand erosion patterns, spurred by earlier rockslides, and worked to preserve the American Falls.

While Niagara Falls remains a breathtaking natural wonder and a top tourist destination, its powerful currents continue to conceal mysteries and tragedies beneath its surface.