Rain from a stalled thunderstorm caused six dams to fail, flooding Johnstown, Pennsylvania, resulting in 84 deaths and $340 in damages.

Johnstown flood of 1977

Natural disaster in Pennsylvania

The Johnstown flood of 1977 was a major flood which began on the night of July 19, 1977, when heavy rainfall caused widespread flash flooding in Cambria County, Pennsylvania, United States, including the city of Johnstown and the Conemaugh Valley.