10 Essential Facts About the Johnstown Flood

On May 31, 1889, between 3 and 3:15 p.m., the South Fork Dam on Pennsylvania's Little Conemaugh River collapsed, unleashing 20 million tons of water from its reservoir toward Johnstown, Pennsylvania. Within an hour, the floodwaters reached the city, leaving its 30,000 residents powerless against the devastation. This catastrophic event has been extensively documented in numerous historical records and eyewitness testimonies.

Despite its legendary status in American history, many aspects of the Johnstown Flood remain unclear. What caused the dam to fail? Who was accountable? And why did a similar failure occur years later? These 10 key facts about the Johnstown Flood aim to shed light on these lingering questions.

1. It remains the deadliest flood in U.S. history.

Even today, the 1889 Johnstown flood stands as the most catastrophic dam failure in U.S. history. Officially, 2,209 lives were lost, encompassing 99 families and 396 children (though some victims may never have been identified). The disaster left 124 women and 198 men widowed, and more than 750 victims were laid to rest in the Plot of the Unknown at Johnstown’s Grandview Cemetery, their identities never uncovered. Some bodies were recovered as far as Cincinnati, and others were found as late as 1911.

The financial impact was equally staggering. The flood obliterated 1,600 homes and inflicted $17 million in property damage ($550 million in today’s dollars). Four square miles of Johnstown’s downtown were utterly annihilated. The massive wave that struck the city reached heights of 40 feet and spanned half a mile in width. Moving at 40 miles per hour, the floodwaters carried debris from neighboring towns like South Fork, Mineral Point, East Conemaugh, and Woodvale. As stated by the Johnstown Area Heritage Association, “contemporary engineers likened the water’s force to that of Niagara Falls.” The debris—which at one point ignited—covered 30 acres after the waters receded.

2. The Johnstown Flood resulted from negligence.

Many historians attribute the disaster to the negligent management of the South Fork Fishing and Hunting Club, which oversaw the dam. This exclusive retreat catered to affluent industrialists like Andrew Carnegie. The club purchased the land from a former congressman, who had acquired it from the Pennsylvania Railroad Company.

The dam had previously failed in 1862—fortunately, the reservoir was not full at the time—and was already in disrepair when the club assumed control. Disregarding local safety standards and performing inadequate repairs by unqualified individuals, the club exacerbated the dam's instability, turning it into an even greater flooding risk.

Rather than increasing the dam's height, they reduced it to accommodate a road and filled the lake to its maximum capacity. They added screens to the spillways to prevent fish from escaping, but these also blocked debris and hindered water drainage. Most critically, the previous owner had removed and sold the cast-iron discharge pipes essential for draining the reservoir after heavy rains, and the club failed to replace them—leaving no way to lower the water level. When intense storms and torrential rains struck in the days leading up to the flood, the stage was set for catastrophe.

3. Repeated warnings to fix the dam were disregarded.

Concerned about the safety of his enterprises, Daniel J. Morrell, the general manager of the Cambria Iron Company in Johnstown, dispatched his engineers to assess the dam years prior to its catastrophic collapse in 1889. After receiving alarming reports, Morrell raised his concerns with the South Fork Fishing and Hunting Club.

Despite an initial lack of progress, Morrell persisted; he became a member of the club to advocate for repairs from within. His strategy might have succeeded had he not passed away in 1885 at the age of 64. Following his death, his membership was handed over to a colleague at the Iron Company, Cyrus Elder—but their efforts ultimately failed.

4. The residents of Johnstown were convinced the dam would hold.

The collapse of the South Fork Dam did not occur without some warning. On the morning of the catastrophe, John Parke, an engineer employed by the South Fork Fishing and Hunting Club to evaluate their sewage system, made a futile attempt with a few others to strengthen the dam and avert total failure. At Parke’s urging, the club dispatched three telegrams to Johnstown, situated roughly 14 miles from the reservoir, with the final message arriving at 3 p.m.—just moments before the breach. The alerts had little impact: As dam operator D.M. Montgemery later recalled, “no one took it seriously. I certainly didn’t. It felt like just another rumor.” This skepticism likely stemmed from the fact that, as one witness put it, warnings about the dam’s failure “had been issued almost every year.”

Years later, Gertrude Quinn Slattery, a Johnstown resident who was only 6 during the flood, described the chaos that followed the deluge. Swept away by the current, she clung to a “makeshift raft made of a soggy, muddy mattress and bedding.” Meanwhile, Anna Fenn Maxwell found herself trapped in a room with her seven children as the water rose. She survived, but her children and husband, who had already been carried away by the flood, did not.

5. The flood marked the Red Cross’s first peacetime disaster relief operation.

The widespread destruction in Johnstown and nearby regions prompted numerous relief initiatives. Over 100 local newspapers and magazines covered the flood. While the reports were not always accurate, they effectively spurred donations of money, clothing, furniture, and food from readers. Medical teams arrived with supplies, and the town received lumber to help rebuild its structures.

The most significant relief operation was spearheaded by the American Red Cross, established in 1881 by nurse Clara Barton. Barton and her team reached Johnstown on June 5, distributing hot meals and offering medical aid. They also established shelters, known as “Red Cross Hotels,” some of which remained operational into the early 1890s.

6. The South Fork Fishing and Hunting Club blamed the disaster on an “act of God.”

The South Fork Fishing and Hunting Club’s owners avoided accountability for the Johnstown Flood. Despite multiple lawsuits, the club claimed the disaster was an “act of God” that was impossible to prevent. The lawsuits largely failed due to the club’s wealthy and influential members, but the legal fallout from the 1889 flood prompted the establishment of stricter regulations to assign liability.

Not only did the club evade legal consequences, but it also avoided compensating the flood’s numerous victims, sparking widespread anger among Johnstown’s survivors and others. According to the JAHA website, “The Johnstown Flood symbolized what many Americans believed was wrong with the country. Many viewed the club’s members as ‘robber barons’ who had escaped justice.” (Although not legally liable, some members did contribute to relief efforts voluntarily.)

In the end, the only party held accountable in court was the dam’s former owner: the Pennsylvania Railroad Company, which lost two cases related to property damage.

7. The club has since become a symbol of local infamy.

The exact role of the South Fork Fishing and Hunting Club in causing the Johnstown Flood remains uncertain; a 1981 report by the American Society of Civil Engineers determined that the dam would have collapsed even without the club’s modifications. The club dissolved in 1904, and many of its records were likely lost when the law firm representing it moved offices in 1917, leaving the mystery unresolved.

Visitors to Johnstown’s National Memorial often inquire about the club’s role and responsibility. “Even the most reserved visitors can become passionate when the club is mentioned,” National Park Service Ranger Nathan Koozer told The Tribune-Democrat in 2014. “Many are convinced the club members were directly responsible for the tragic loss of life.”

8. New discoveries about the Johnstown Flood continue to emerge.

While historians and journalists have extensively covered the club’s actions, key details about the dam’s failure—such as which parts failed first, why, and how—remain elusive. Previously hindered by a lack of historical records, researchers are now revisiting the disaster using advanced digital tools.

Recently, the University of Pittsburgh-Johnstown employed ground-penetrating radar to study the dam site and the floodwaters’ speed and volume. This innovative approach revealed new insights: As reported in a 2015 Times Record article, the findings “indicate the dam was designed with two spillways for heavy rainfall, but only one was operational.”

9. Johnstown experienced flooding again after the 1889 disaster.

Following the flood, no federal, state, or local laws were enacted to prevent future tragedies. As a result, the 1889 flood was not the final instance of the city being inundated. Beyond minor seasonal floods that regularly affected streets and basements, two significant floods occurred in 1936 and 1977.

The 1936 flood, triggered by heavy snow and rain, resulted in approximately two dozen deaths, the destruction of 77 buildings, and around $41 million in property damage. The 1977 flood, caused by intense thunderstorms that breached multiple dams, claimed 85 lives and caused $300 million in damages. Due to its recurring flood history, Johnstown is often nicknamed “Flood City.”

10. Despite its challenges, Johnstown remains a thriving community.

Each subsequent flood after 1889 led to significant improvements aimed at enhancing Johnstown’s safety. In 1936, the Works Progress Administration hired workers to excavate the town, remove debris, rebuild sidewalks, and erect new bridges. Following the 1977 flood, the federal government allocated $200 million in aid and grants to help residents rebuild more resiliently.

These initiatives have ensured Johnstown remains a vibrant community. The South Fork Dam site has been transformed into the Johnstown Flood National Memorial, which collaborates with the Johnstown Flood Museum in the city center. Today, Johnstown has a population of approximately 18,000 and hosts a campus of the University of Pittsburgh. Appropriately, visitors can find markers throughout the city indicating the water levels from each of the three major floods.