AI researcher and running influencer Yoo Ji-won dies near Seoul half-marathon finish

On Oct 11, during the Seoul Race half-marathon, 25-year-old Yoo Ji-won collapsed just 500 metres before the finish line at the 20.6 km point. Yoo, who combined a career as a semiconductor researcher at KAIST with a growing online presence as @mta1n_0ne, was rushed to a local hospital after immediate medical assistance on the course, but she died despite those efforts. The race organizers issued a statement mourning her loss, offering sympathy to her family and fellow participants, and pledged to examine the event’s safety protocols.

While her exact cause of death remains pending, tributes flooded social media, and her final Instagram post has become a digital memorial. Yoo had previously won the women’s masters 10 km title at the Gunsan Saemangeum Marathon and completed the full Seoul Marathon in under three hours.