Dawid Moszek David Max Wajskopf - mystery

So David Moszek Wajskopf born on 2/12/08 was the son of Cyna and Golda B, Wajskopf and survived. My apologies I did a page of testimony for him based on a Lodz record that listed a deportation date for him and I must of assumed that he was deported to Chelmno like most were, including members of his family. But I am confused as to another record I found in the Arolsen Archives that states a Dawid Wajskopf born in March 23, 1909, in Lodz was the son of Cyna and GOlda B. Wajskopf and this Dawid Wajskopf went to Canada and died on APril 1, 1984 and was buried there, Jewishgen has a photo of his gravestone. How are there two David Weiskopfs with the same parents??