As Japan commemorated the 30th anniversary of the sarin gas attack by the doomsday cult Aum Shinrikyo in Matsumoto, Nagano Prefecture, on Thursday, a doctor who dealt with the crisis reflected on the critical importance of passing down knowledge and experience to future generations.

On June 27, 1994, the gas attack in a residential area in Matsumoto claimed eight lives and injured over 140. Hiroshi Okudera, 68, who treated victims at Shinshu University Hospital in the city, has spent three decades ensuring the lessons from the tragic incident are not forgotten.

Okudera, who now practices at the Central Japan International Medical Center in Minokamo, Gifu Prefecture, vividly remembers the moment he learned of the attack. Firefighters knocked on his door, alerting him to the disaster unfolding near his home.