The terrible Johnstown Pennsylvania Flood of 1889 was more of a man-made Tsunami. Yes, there was flooding at first, when ‘Storm of the Century’ rains arrived in the deep Alleghany valley on Memorial Day 1889, and the two rivers that flanked the steel mill town swelled. But it wasn’t until the aging South Fork Dam, that held back Lake Conemaugh,14 miles upriver burst, that the REAL tragedy occurred for poor unsuspecting Johnstown.
