On October 12, 1960, Asanuma was assassinated by 17-year-old 
Otoya Yamaguchi, a 
nationalist, during a televised political debate for the coming elections for the 
House of Representatives. While Asanuma spoke from the lectern at Tokyo's Hibiya Hall, Yamaguchi rushed onstage and ran his 
yoroi-dōshi (a traditional samurai sword) through Asanuma's ribs on the left side, killing him. Japanese television company 
NHK was videorecording the debate for later transmission and the tape of Asanuma's assassination was shown many times to millions of viewers.
[6][7] The photograph of Asanuma's assassination won its photographer 
Yasushi Nagao both the 
Pulitzer Prize and 
World Press Photo of the Year.
[2]
Yamaguchi was captured at the scene of the crime, and a few weeks afterwards committed suicide by hanging while in police custody.