In the story, The Seventh Man, K died as a result of a typhoon attack.
What killed the Seventh Man?
K's death serves as a significant moment that shapes the protagonist's life. During a fierce typhoon, K, the protagonist's childhood friend, is swept away by a massive wave while they are exploring the aftermath of the storm. The protagonist, who narrowly escapes the same fate, has to deal with the guilt and trauma of K's death.
The typhoon, a force of nature beyond human control, represents the unpredictability and fragility of life. K's sudden and tragic demise also served as a harsh awakening for the protagonist, forcing him to confront the inevitability of death and the fragility of human existence.