What Happened on December 21, 2021 - On This Day
www.onthisday.com › date › 2021Dec 21, 2021 · 2021 December 21 Historical Events Major breakthrough in development of nuclear fission energy when experiment produces 59 megajoules of energy over five seconds at JET Laboratory, UK (reported Feb 2022) [1] Famous Deaths (Wilbert) Billy Davis, American tennis player (11 x American Tennis Association Titles), dies of congestive heart failure at 91