This movie was a monumental undertaking for 20th Century-Fox. Of the 100 shooting days, almost half were spent filming the man-made rain and floods, for which 33 million gallons of water were used.
The first movie to win an Oscar for Best Visual Effects. The category was called Best Special Effects and included both sound and photographic winners for Edmund H. Hansen and Fred Sersen respectively.
During filming in 1939, Myrna Loy had a narrow escape when her horse bolted while shooting a scene; she was nearly killed.
Initially budgeted at $2.5 million, an additional $100,000 was added to film a new ending, $500,000 was allotted for the sets and $500,000 for the flood and earthquake scenes. An army of 350 grips, carpenters and laborers worked for more than a month on those scenes.