<a href="https://en.wikipedia.org/wiki/Nuclear_weapons_testing" id="mwAQ4" rel="mw:WikiLink" title="Nuclear weapons testing">Nuclear weapons testing</a>: The <a href="https://en.wikipedia.org/wiki/Castle_Bravo" id="mwAQ8" rel="mw:WikiLink" title="Castle Bravo">Castle Bravo</a>, a 15-<a href="https://en.wikipedia.org/wiki/TNT_equivalent" id="mwARA" rel="mw:WikiLink" title="TNT equivalent">megaton</a> <a class="mw-redirect" href="https://en.wikipedia.org/wiki/Hydrogen_bomb" id="mwARE" rel="mw:WikiLink" title="Hydrogen bomb">hydrogen bomb</a>, is detonated on <a href="https://en.wikipedia.org/wiki/Bikini_Atoll" id="mwARI" rel="mw:WikiLink" title="Bikini Atoll">Bikini Atoll</a> in the Pacific Ocean, resulting in the worst <a href="https://en.wikipedia.org/wiki/Radioactive_contamination" id="mwARM" rel="mw:WikiLink" title="Radioactive contamination">radioactive contamination</a> ever caused by the United States.