As a teenager, he was actively involved in recruiting anti-Japanese guerrillas for his long-time friend, Kim Il Sung, and is remembered as being unusually tall and often towering over others.

Kang was known as a ruthless soldier, as was reflected in the armies he commanded; they were aggressive, insensitive to risk, and eager for a victory by August 15, as Kim Il Sung demanded.

[13] On August 4, the morning that began the Battle of Pusan Perimeter, Kang was injured when his makeshift command post (an abandoned meat-packaging plant, selected for its thick concrete walls, originally constructed for refrigeration) was struck by a 500-pound bomb.

[14] On September 8, 1950, Kang's car was clown by a land mine near Kŭm River in the southern part of Korea killing him.

[15] He was awarded "Hero of the Republic"[16] and two days after his death, Kim Il Sung held a funeral for his fallen, long-time comrade in Pyongyang.