According to the reports, a power outage occurred on the Japan Railway (JR) Ōu Line of Yamagata Branch of the East Japan Railway Company (JR East) at approximately 1319 hours (local time) on Saturday (06 December). This resulted in the complete suspension of Yamagata Shinkansen and Ōu Line services between Yonezawa and Yamagata.

• The power outage occurred between Akayu Station (Nanyō City, Yamagata Prefecture) and Mokichi Memorial Hall Station (Kaminoyama City, Yamagata Prefecture).
• The JR East stated that the cause of the outage remains under investigation.
• Replacement transportation services have not yet been announced, and further updates will be communicated through official JR East/Japan Railways channels.