What is the story Hurston hears about the Johnstown flood in the book, Mules and Men?

James Mosely tells a story about angels who rolled barrels of water so quickly that they broke and caused the Johnstown flood. A black man who drowned in the flood went to heaven and told everyone about the flood. One man in heaven was very rude and refuysed to listen to the story. Upon further questioning, Saint Peter said that man was Noah, and there was probably nothing he didn't already know about floods.