The younger one, Flight Lieutenant Michael Oser Weizmann (1916–1942), fought in the Royal Air Force during World War II. While serving as a pilot in No. 502 Squadron RAF, he was killed when his plane was shot down over the Bay of Biscay in February 1942. His body was never found and he was listed as "missing". His father never fully accepted his death and made a provision in his will, in case he returned. He is one of the British Empire's air force casualties without a known grave commemorated at the Air Forces Memorial at Runnymede in Surrey, England.