It was when President Kim Il Sung worked at Kosanjin.

One day the President visited a unit of the People's Army and learned that some soldiers had taken ownerless oxen to the unit on their way to temporary strategic retreat.

He said that they should be well reared and taken back to their owners. 

A few days later the unit had to move but they had problem with oxen. 

Just as the soldiers were going to load oxen on a military train, station officials flied into rages. 

The President was made a report and wrote a letter on offering every possible accommodation for urgent transportation of oxen and sent it to the chief official of the station. 

Later, a legendary story became well-known among the people that the oxen to be taken to their owners were transported as “special guests” by a military train.