<a href="https://en.wikipedia.org/wiki/The_Holocaust" id="mwwQ" rel="mw:WikiLink" title="The Holocaust">The Holocaust</a>: <a href="https://en.wikipedia.org/wiki/Nazi_Germany" id="mwwg" rel="mw:WikiLink" title="Nazi Germany">Nazi Germany</a> carries out its final use of <a href="https://en.wikipedia.org/wiki/Gas_chamber" id="mwww" rel="mw:WikiLink" title="Gas chamber">gas chambers</a> to execute 33 Upper Austrian socialist and communist leaders in <a href="https://en.wikipedia.org/wiki/Mauthausen_concentration_camp" id="mwxA" rel="mw:WikiLink" title="Mauthausen concentration camp">Mauthausen concentration camp</a>.<sup about="#mwt40" class="mw-ref reference" data-mw='{"name":"ref","attrs":{},"body":{"id":"mw-reference-text-cite_note-6"}}' id="cite_ref-6" rel="dc:references" typeof="mw:Extension/ref"><a href="./April_28#cite_note-6" id="mwxQ" style="counter-reset: mw-Ref 6;"><span class="mw-reflink-text" id="mwxg">[6]</span></a></sup>
<span class="mw-reference-text" id="mw-reference-text-cite_note-6"><cite about="#mwt37" class="citation web cs1" id="mwBnA"><a class="external text" href="https://encyclopedia.ushmm.org/content/en/article/1945-key-dates" id="mwBnE" rel="mw:ExtLink nofollow">"1945: Key Dates"</a>. <i id="mwBnI">encyclopedia.ushmm.org</i><span class="reference-accessdate" id="mwBnM">. Retrieved <span class="nowrap" id="mwBnQ">2022-01-17</span></span>.</cite><span about="#mwt37" class="Z3988" id="mwBnU" title="ctx_ver=Z39.88-2004&amp;rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&amp;rft.genre=unknown&amp;rft.jtitle=encyclopedia.ushmm.org&amp;rft.atitle=1945%3A+Key+Dates&amp;rft_id=https%3A%2F%2Fencyclopedia.ushmm.org%2Fcontent%2Fen%2Farticle%2F1945-key-dates&amp;rfr_id=info%3Asid%2Fen.wikipedia.org%3AApril+28"></span></span>