publication date: Tuesday, April 11, 2006 (part of Round XXVII)
clue: Jeez, the worst thing I ever tried to make in my parents' backyard was a treehouse.
explanation: Hahn was 17 when he attempted to build a nuclear reactor in his backyard toolshed, eventually generating so much toxic radiation that he was investigated by the Nuclear Regulatory Commission and his parents' backyard declared a Superfunds hazarous materials cleanup site. more…
trivia: The source image comes from the biography The Radioactive Boy Scout.