In the early 20th century , the population reached 75,000 people . The city 's first commercial radio station , WJAC , began broadcasts in 1925 . The downtown boasted at least five major department stores , including Glosser Brothers , which in the 1950s gave birth to the Gee Bee chain of department stores . However , the St Patrick 's Day flood of 1936 combined with the gnawing effects of the Great Depression left Johnstown struggling again , but only temporarily . Johnstown 's citizens mobilized to achieve a permanent solution to the flooding problem and wrote to President Franklin Roosevelt pleading for federal aid . Starting in August 1938 , continuing for the next five years , the U. S. Army Corps of Engineers gouged , widened , deepened , and realigned of river channel in the city , and encased the river banks in concrete and reinforced steel . In a campaign organized by the Chamber of Commerce , thousands of Johnstown 's citizens wrote to friends and relatives across the country hoping to bring new business to the town . Professional ice hockey would find a home in Johnstown , starting in 1941 with the Johnstown Blue Birds for one season and returning in 1950 with the Johnstown Jets . The Jets later hosted an exhibition game against Maurice Richard and the Montreal Canadiens on November 20 , 1951 . The memory of floods was virtually purged from the community 's consciousness . Newcomers to the town heard little about the tragic past . Johnstown proclaimed itself " flood-free " , a feeling reinforced when Johnstown was virtually the only riverside city in Pennsylvania not to flood during Hurricane Agnes in 1972
flood of 1936
Johnstown flood of 1936
Johnstown, Pennsylvania