On May 31, 1889, Pennsylvania’s South Fork Dam collapsed,
causing the catastrophic Johnstown Flood. More than 2,200
people died in the disaster.
Located 60 miles east of Pittsburgh in a valley near the
Allegheny, Little Conemaugh and Stony Creek Rivers,
Johnstown sits on a floodplain subject to frequent
disasters.
In 1840, officials constructed a dam on the Little Conemaugh
River, 14 miles upstream from Johnstown. Nine hundred feet
by 72 feet, it stood as the largest earthen dam in the United
States, creating the largest man-made lake of the time,
Lake Conemaugh.
The dam was part of an extensive canal system that became
obsolete as the railroads replaced the canal as a means of
transporting goods. As the canal system fell into disuse,
maintenance on the dam was neglected.
In 1889, Johnstown was home to 30,000 people, many of
whom worked in the steel industry.
On May 31, the residents were unaware of the danger that
steady rain over the course of the previous day had caused.
One of the American Red Cross’s first major relief efforts took
place in the aftermath of the Johnstown flood. Clara Barton
arrived five days later to lead the relief. It took five years to
rebuild Johnstown, which again endured deadly floods in
1936 and 1977.
A Harper’s Weekly sketch.
Severe damage along Main Street in Johnstown.
