The Johnstown flood of 1977; also known as the Second great flood of Johnstown, and the Johnstown disaster, began on the night of 20 July 1977 when flash floods hit the area of Cambria County, around Johnstown, Pennsylvania and the Conemaugh Valley. Nearly twelve inches of rain fell in twenty-four hours, when a thunder storm stalled over the area. With the failing of six area dams nature was able to do what area residents had been convinced could not happen again.
Ron Shawley, executive director of Laurel Highland’s Historical Village, returned to Johnstown on the 20th and stated “It was like somebody dropped an atomic bomb on Johnstown”, “I questioned what kind of force it would take to do that.”.