The volcano <a href="https://en.wikipedia.org/wiki/Nevado_del_Ruiz" id="mw9w" rel="mw:WikiLink" title="Nevado del Ruiz">Nevado del Ruiz</a> erupts and melts a <a href="https://en.wikipedia.org/wiki/Glacier" id="mw-A" rel="mw:WikiLink" title="Glacier">glacier</a>, causing a <a href="https://en.wikipedia.org/wiki/Lahar" id="mw-Q" rel="mw:WikiLink" title="Lahar">lahar</a> (volcanic mudslide) that <a href="https://en.wikipedia.org/wiki/Armero_tragedy" id="mw-g" rel="mw:WikiLink" title="Armero tragedy">buries Armero, Colombia</a>, killing approximately 23,000 people.