The leader of North Korea, Kim Jong-il, has died and South Korea's military is now on alert.<br /><br />Many in the region are nervous about the transition of power to his likely successor and young son.<br /><br />Back in North Korea, a very public outpouring of grief is under way for a leader who kept a very tight grip on power and the people he ruled. <br /><br />Al Jazeera's Melissa Chan reports from Beijing, China.
