<a href="https://en.wikipedia.org/wiki/Humberto_Vidal_explosion" id="mwAUo" rel="mw:WikiLink" title="Humberto Vidal explosion">Humberto Vidal explosion</a>: Thirty-three people die when a Humberto Vidal shoe shop in <a href="https://en.wikipedia.org/wiki/Río_Piedras,_Puerto_Rico" id="mwAUs" rel="mw:WikiLink" title="Río Piedras, Puerto Rico">Río Piedras, Puerto Rico</a> explodes.