For the first installment of MMT, we refer back to the Modern Mechanix article on movie spfx in this post.
"Deluge" (1933 RKO) was an early disaster film with some of the best miniature effects seen up to that time. It was often mentioned (usually accompanied by stills) in FM and other monster mags. The film was thought "lost", for many decades, until an Italian dubbed print turned up in the 1980s. The disaster footage had been available because of it's reuse in several serials.