Before fleeing his northern stronghold, <a href="https://en.wikipedia.org/wiki/Khmer_Rouge" id="mwAW0" rel="mw:WikiLink" title="Khmer Rouge">Khmer Rouge</a> leader <a href="https://en.wikipedia.org/wiki/Pol_Pot" id="mwAW4" rel="mw:WikiLink" title="Pol Pot">Pol Pot</a> orders the killing of his defense chief <a href="https://en.wikipedia.org/wiki/Son_Sen" id="mwAW8" rel="mw:WikiLink" title="Son Sen">Son Sen</a> and 11 of Sen's family members.