By Sid Perkins
PORTLAND, Ore. — The devastating flow released when a dam burst upstream of Johnstown, Pa., in May 1889 transformed a small, normally tranquil river into a raging torrent that briefly rivaled the mighty Mississippi, a new study reveals.
![](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2009/10/11230.jpg?resize=300%2C187&ssl=1)
Johnstown, which lies about 100 kilometers east of Pittsburgh, was a thriving coal- and iron-producing town in the years following the Civil War, says Carrie Davis Todd, a hydrologist at the University of Pittsburgh at Johnstown. Then, on the rainy afternoon of May 31, 1889, disaster struck: A dam about 23 kilometers upstream of the town burst, sending a wall of debris-filled water down the narrow valley of the Little Conemaugh River to ravage the town. More than 2,200 people died in the disaster — a death toll aggravated by the fact that even before the dam burst, flood waters filling the streets of Johnstown had trapped many residents in their homes, she reported here October 19 at the annual meeting of the Geological Society of America.
Despite the event’s massive death toll, few detailed studies of the flood have been done, says Dan Ingram, curator at the Johnstown Area Heritage Association. “There’s a ton of anecdotal information, but few people have ever looked at it in a scientific way,” he notes.