LDS periodical says entire population of the world except Noah and his family were destroyed by the Flood.
"The Situation in the Last Days," The Latter-day Saints' Millennial Star 43, no. 36 (September 5, 1881): 568–569
These he called Prophets. Sometimes he selected one only, at other times he chose several, who contemporaneously warned the various nations of peoples of the earth concerning important coming events. For proof of this method we have but to introduce the case of Noah, who warned the ante-deluvians of the coming deluge. The revelation for the entire world of mankind, informing them of the approach of that dire event, was given to one man,—Noah, and by him communicated to the people. God held them responsible for the acceptance or rejection of his lone testimony. They did not believe his words, they rejected his message, but the multitude of their unbelief and opposition did not prevent the fulfillment of his inspired prediction. "The floods came and destroyed them," and but seven out of the whole population were saved with the Prophet in the Ark.