Final answer:
The disaster that destroyed Johnstown was caused by the failure of the South Fork Dam. The responsibility for the failure lies with the South Fork Fishing and Hunting Club.
Step-by-step explanation:
The disaster that destroyed Johnstown was the result of the failure of the South Fork Dam, which caused a massive flood. The flood occurred on May 31, 1889, and resulted in the deaths of more than 2,200 people. While there were many individuals and organizations involved in the response and recovery efforts after the disaster, the overall responsibility for the failure of the dam lies with the South Fork Fishing and Hunting Club, which owned the dam and neglected to properly maintain it.