` ` An insecure North Korea could ( be ) more dangerous , '' a U.S. official says . `` South Korea 's concern is warranted , frankly , because an insecure North Korea could well be an even more dangerous North Korea , '' a U.S. official said . South Korea 's national security council is critical , its spokesman says . Kim died of a heart attack while on a train , North Korea 's state news agency reports . Kim Jong Il was the son of Kim Il Sung , the leader of the communist nation .
` ` An insecure North Korea could ( be ) more dangerous , '' a U.S. official says . South Korea 's national security council is critical , its spokesman says . Kim died of a heart attack while on a train , North Korea 's state news agency reports . Kim Jong Il was the son of Kim Il Sung , the leader of the communist nation .