Johnstown Flood
National Memorial
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"A Roar Like Thunder"

On June 1, 1889, Americans woke to the news that Johnstown, Pennsylvania, had been devastated by the worst inland flood in the nation's history. More than 2,200 were dead, with thousands more injured. When the full story of the flood came to light, many realized that this was more than a natural disaster—that greed and self-interest were powerful accomplices.

Johnstown in 1889 was a steel company town of German and Welsh families. It was a growing and industrious community of 30,000, known for the quality of its steel. Founded in 1794, Johnstown began to prosper with the building of the Pennsylvania Mainline Canal in 1834 and the arrival of the Cambria Iron Company and Pennsylvania Railroad in the 1850s.

There was one drawback to living in the city. Johnstown had been built on a floodplain at the fork of the Little Conemaugh and Stonycreek rivers. Over the years the growing city had stripped forests from the surrounding hills and narrowed the river banks to gain building space. Without the trees to slow runoff, rainwater was forced into the constricted river channel; heavy annual rains had dramatically increased flooding.

And there was something else. Fourteen miles up the Little Conemaugh, two-mile-long Lake Conemaugh was held on the side of a mountain—450 feet higher than Johnstown—by the old South Fork Dam. The dam was poorly maintained, and there was talk that the dam might not hold. But it always had, and the supposed threat became a standing joke around town.

On the afternoon of May 31 town residents heard a low rumble that grew to a "roar like thunder." After a night of heavy rain the South Fork Dam had finally broken, sending 20 million tons of water crashing down the narrow valley. Most people never saw anything until the 36-foot wall of water, boiling with huge chunks of debris, rolled over them at 40 miles per hour, consuming everything in its path. Those who saw the water said it "snapped off trees like pipestems," "crushed houses like eggshells," and "threw around locomotives like so much chaff." A violent wind preceded it, blowing down small buildings. Making the wave even more terrifying was the black pall of smoke and steam from burst boilers that hung over it—the "death mist" remembered by survivors.

Thousands of people desperately tried to escape the wave, but they were slowed as in a nightmare as deepening water covered the town. One observer on a hill said the streets "grew black with people running for their lives." Some remembered reaching the hills and pulling themselves out of the flood path seconds before it overtook them. Those caught by the wave found themselves swept up in a torrent of oily, yellow-brown water, surrounded by tons of grinding debris that crushed some and provided rafts for others. Many became helplessly entangled in miles of barbed wire from the destroyed Gaultier Wire Works. People who were indoors raced upstairs seconds ahead of the rising water, which reached the third story in many buildings. Some never had a chance, as homes were crushed or ripped from foundations, adding to the churning rubble. People clinging to debris struggled to keep their balance as their rafts pitched in the flood.

It was over in 10 minutes—but for some the worst was to come. Thousands of people were stranded in attics or on roofs of buildings that withstood the initial wave but were now threatened by the 20-foot-deep current that tore at foundations. In the growing darkness they watched buildings topple, not knowing if theirs would last the night.

The most harrowing experience for hundreds came at the stone railroad bridge below the junction of the rivers. Thousands of tons of debris scraped from the valley, along with a good part of Johnstown, piled up against the bridge's arches. The 45-acre mass held homes, machinery, freight cars, railroad track, bridge sections, boilers, telegraph poies, trees, animals, and hundreds of people. The oil-soaked jam was immovable, held against the bridge by the current and bound tight by the barbed wire.

Some people were able to scramble over the heap to shore. Many were trapped in the wreckage or snared in the wire, unable to move. Then the oil caught fire. As rescuers worked in the dark to free people, flames spread over the whole mass, burning with "all the fury of hell," according to a Johnstown newspaper. More than 80 people died at the bridge, some still in their own homes.

The next morning an eerie silence hung over Johnstown. The water receded during the night, leaving vast heaps of rubble in the streets (where there were streets). Entire blocks were destroyed. Hundreds of people, alive and dead, lay buried in debris and mud.

Many bodies were never identified, and hundreds of the missing were never found. Disease followed in the wake of the flood, and typhoid added 40 more lives to the 2,209 lost in the flood. Emergency morgues and hospitals were set up, and commissaries distributed food and clothing. The nation responded to the disaster with an outpouring of time, money, food, and clothing. Contributions from the United States and other countries totaled more than $3,700,000.

Property damage was $17 million. The cleanup operation took years, with bodies still being found months (and years) after the flood. The city regained its population and rebuilt its manufacturing centers, but it was years before Johnstown fully recovered.

Retreat for the Rich

On Lake Conemaugh, the South Fork Fishing and Hunting Club was an exclusive and somewhat secretive retreat for the Pittsburgh rich. They repaired the old dam, raised the lake level, and built a clubhouse and cottages. The members enjoyed hunting, sailing, and cruising on two excursion steamers. But the club did not maintain the dam well, and it weakened dangerously.

The Flood Paths

When the flood struck Johnstown, the wave divided: part followed the river channel and the rest headed downtown. Large buildings split the second wave again. Water roared down Clinton and Jackson streets; the rest plowed directly through town. The central wave crashed into the sheer hillside at Stonycreek River, causing a backwash up the river and a violent whirlpool above the stone bridge.

A Wild Ride

Victor Heiser recalled: "The townspeople, like those who live in the shadow of Vesuvius, grew calloused to the possibility of danger." Heiser was in the family barn when the flood struck. He saw his home, with his parents in it, crushed and swept away. Clinging to the barn roof, he had a wild ride down the Conemaugh River and then up Stonycreek River on the backwash, ending up in Kernville.

Aid from the Red Cross

Clara Barton, known as the "Angel of the Battlefield" during the Civil War, arrived five days after the flood. It was the first test of her newly formed American Red Cross. With a staff of 50 doctors and nurses, she surveyed the injured, set up hospital tents, built six "Red Cross hotels" for the homeless, and distributed food, clothing, and medicine.

Unknown Flood Victims

Grandview Cemetery contains graves of the unknown flood victims. In the disaster 99 families were wiped out, and 98 children were orphaned. After the flood, Major John Wesley Powell wrote: "Modern industries are handling the forces of nature on a stupendous scale . . .. Woe to the people who trust those powers to the hands of fools."

"Our Misery Is the Work of Man"

Warnings about a possible flood reached the people of Johnstown three times in the hours before the dam broke—but they had heard those kinds of warnings before. The South Fork Dam, one of the largest earthen dams in the world, had always held during high water. Besides, wasn't the dam maintained by some of the richest men in America?

The South Fork Fishing and Hunting Club, made up of Pittsburgh industrialists and businessmen such as Andrew Carnegie and Andrew Mellon, had bought the lake and dam nine years earlier to use as a summer retreat. The reservoir was originally built to supply water for the Pennsylvania Mainline Canal, and the dam met accepted engineering practices of the time. But the canal system was obsolete by the time the dam was completed in 1853, and the Pennsylvania Railroad bought it four years later. In 1862 a break occurred near the discharge pipes, draining the lake, but little damage resulted because the lake level was low at the time. The railroad abandoned the dam and it deteriorated until 1879, when it was bought by the South Fork Club.

At first the 72-foot-high dam frightened some residents of Johnstown. Said one: "No one could see the immense height to which that artificial dam had been built without fearing the tremendous power of the water behind it .. . . People wondered and asked why the dam was not strengthened, as it certainly had become weak, but nothing was done, and by and by they talked less and less about it." Others, realizing their continuing vulnerability, called the dam "the sword of Damocles hanging over Johnstown." Daniel Morrell, president of Cambria Iron, asked the South Fork Club to strengthen the dam. The club's president refused, saying: "You and your people are in no danger from our enterprise."

On the morning of May 31, 1889, in a farmhouse above the dam, Elias Unger (current president of the South Fork Club) awoke to the sight of a lake swollen after a night of torrential rain. Unger rushed to the dam to assess the situation. Horrified, he saw water nearly cresting the dam. Unger acted quickly to try to save it. Soon a group of men were atop the South Fork Dam—some plowing the earth to raise it, some digging another spillway at the other end, and some trying to plug leaks with whatever materials they could find.

John Parke, an engineer for the South Fork Club, briefly considered cutting through the dam's end, where the pressure would be less. Feeling that he would be held responsible for flooding the valley, Parke decided against it. Unger, Parke, and the others worked until they were exhausted.

When he dam started to break at 3:10 pm, Parke wrote later, "the fearful rushing waters opened the gap with such increasing rapidity that soon after the entire lake leaped out .... It took but forty minutes to drain that three miles of water." One observer said the water "roared like a mighty battle." Ten million tons of water took its natural course, dropping 450 feet in 14 miles, at times in a wall 70 to 75 feet high traveling 40 miles per hour. Telegraph lines were down, and Johnstown received no more warnings. In 57 minutes the wave engulfed the town. Over 2,200 people were unaware that death was moving down the valley.

Understanding the Johnstown Flood

In the Flood's Wake

Lake Conemaugh broke through the South Fork Dam at the velocity and depth of the Niagara River as it goes over the falls. Farmers below the dam described the wave as "a turbulent wall of water, filling the entire valley." At times the tons of debris gathered by the wave caused it to choke up in the narrow valley, stop momentarily, then explode forward again with greater power. The debris actually spared Johnstown even worse destruction, as it slowed the wave to a maximum speed of about 40 miles per hour. The water would have reached 60 to 90 miles per hour if it had rushed unimpeded down the valley.

The South Fork Dam did not instantly burst. Observers remember the water gouging out a "big notch," then cutting down rapidly through the earth. "The whole dam seemed to push out all at once. Not a break, just one big push."

The 78-foot Conemaugh Viaduct stopped the flood temporarily when debris jammed against its arch. A lake deeper than the original formed, then the viaduct collapsed. In Woodvale only the mills withstood the wave. Miles of barbed wire floated free when the wire works was destroyed, adding to he terror of those caught in the flood.

At the South Fork Dam site are the two abutments and dry lake bed left after the 1889 break. The South Fork Fishing and Hunting Club Historic District preserves eight of the original cottages and the clubhouse in the town of Saint Michael.

South Fork, two miles downstream, was the first town struck by the flood. The water destroyed 20-30 homes. Four people died.

The valley of the Little Conemaugh River below South Fork narrows abruptly. Here the mass of water pushed up 70 to 75 feet. It ripped up railroad track and ties, which joined the flood.

The railroad crossed the river on the 78-foot-high Conemaugh Viaduct at the end of a two-mile-long oxbow. Part of the wave left the river channel, crossed the oxbow and hit the viaduct. Wreckage at the viaduct dammed the water briefly. The rest of the flood followed the river channel, crashing into the viaduct seven minutes later. When the viaduct collapsed, the flood and debris gushed forth with greater violence than at the South Fork Dam.

Mineral Point, one mile below the viaduct, was struck with renewed force. Thirty families lived on the village's single street. After the flood only bare rock remained; 16 people died.

At East Conemaugh a witness said the water was almost obscured by debris that resembled "a huge hill rolling over and over." Train engineer John Hess tried to warn people by tying down his whistle and racing toward town ahead of the wave. His warning saved many but 50 people died, including 25 passengers stranded on trains in town.

The flood gathered speed and power as the river straightened between East Conemaugh and Woodvale, hitting these towns hardest of all. Woodvale, like Johntown, had no warning. Cambria Iron Company's model town was leveled; only part of a mill still stood in a sea of mud. Of the 1,100 residents, 314 died. Boilers exploded when the flood hit Gau1tier Wire Works, creating a black "death mist" seen by Johntown residents.

Today you can see the stone bridge where debris, animals, and humans piled up and caught fire. The stone church that helped split the wave is at the corner of Locust and Franklin streets. The Johnstown Flood Museum (fee), 304 Washington Street, has information and exhibits. You can ride the Johnstown Inclined Plane (fee) for views of the city. Visit Grandview Cemetery to see the graves of unknown flood victims.

More Information

park map
(click for larger map)

Visitor Center Information, exhibits, and a film about the flood Call the park or check the website for hours, programs, and activities.

Accessibility We strive to make our facilities, services, and programs accessible to all. For information go to the visitor center, call, or check the park website.

Getting Here Take US 219 to Saint Michael/Sidman exit. Go east on PA 869. Turn left onto Lake Road to the park.

Safety and Regulations Camping, hunting, and open fires are prohibited. • Do not disturb, damage, or remove plants, animals, or historical objects—all are protected by federal law. • Firearms regulations are on the park website.

Source: NPS Brochure (2016)


Johnstown Flood National Memorial — August 31, 1964

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Brochures ◆ Site Bulletins ◆ Trading Cards expand section


A History of Johnstown and the Great Flood of 1889: A Story of Destruction and Rehabilitation (Nathan D. Shappee, 1940)

Alternative Transportation Study: Johnstown Flood National Memorial Final Report (Clough, Harbour & Associates, LLP and Einhorn Yaffee Prescott, September 2004)

Cultural Landscape Report for Johnstown Flood National Memorial (Jennifer G. Hanna, Emelyn Najera, Kelsey Little and H. Eliot Foulds, 2021)

Cultural Landscapes Inventory, Johnstown Flood National Memorial (J. Killion and D. Friday, 2016)

Draft General Management and Development Plan, Allegheny Portage Railroad National Historic Site and Johnston Flood National Memorial, Pennsylvania (January 1977)

Foundation Document, Johnstown Flood National Memorial, Pennsylvania (October 2013)

Foundation Document Overview, Johnstown Flood National Memorial, Pennsylvania (January 2014)

Geologic Resource Evaluation Report, Johnstown Flood National Memorial NPS Natural Resource Report NPS/NRPC/GRD/NRR-2008/049 (September 2008)

Historic Structure Report, The South Fork Dam, Historical Data, Johnstown Flood National Memorial, Pennsylvania (Harlan D. Unrau, 1979)

Historic Structure Report, Elias J. Unger House, Johnstown Flood National Memorial, Historical and Architectural Data Sections (Ella Sue Rayburn and Sally Small, January 1986)

Impacts of Visitor Spending on the Local Economy: Johnstown Flood National Memorial, 2005 (Daniel J. Stynes, October 2007)

Integrity of benthic macroinvertebrate communities in Allegheny Portage Railroad National Historic Site and Johnstown Flood National Memorial: Eastern Rivers and Mountains Network 2008 summary report NPS Natural Resource Data Series NPS/ERMN/NRDS—2010/025 (Caleb J. Tzilkowski, Kristina K. Callahan, Matthew R. Marshall and Andrew S. Weber, February 2010)

Junior Ranger Activity Booklet (Ages 8-10), Johnstown Flood National Memorial (Date Unknown)

Natural Resource Condition Assessment, Johnstown Flood National Memorial NPS Natural Resource Report NPS/JOFL/NRR-2014/836 (Susan Yetter, Joseph Bishop, Sarah Hurteau, Sarah Chamberlain, Michael Nassry, Hannah Ingram and Robert Brooks, August 2014)

Preservation and Interpretation Plan for the South Fork Fishing and Hunting Club Historic District and Alternatives for Establishing an Interpretive Tour Route Between Johnstown Flood National Memorial and the City of Johnstown (December 1988)

Handbooks ◆ Books expand section


The Johnstown Flood of 1889

Last Updated: 02-Dec-2022